Sqlite tutorial
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This document provides a tutorial on SQLite, an open-source SQL database that does not require a separate server. It begins with an overview of SQLite and its features, then discusses how to install SQLite on different operating systems. The majority of the document describes SQLite syntax, commands, and statements for working with databases, tables, indexes, and data, including examples. It also covers data types and how to create, attach, and detach databases in SQLite.
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SQLite RELEASE SAVEPOINT Statement:
RELEASE savepoint_name;
SQLite REINDEX Statement:
REINDEX collation_name;
REINDEX database_name.index_name;
REINDEX database_name.table_name;
SQLite ROLLBACK Statement:
ROLLBACK;
or
ROLLBACK TO SAVEPOINT savepoint_name;
SQLite SAVEPOINT Statement:
SAVEPOINT savepoint_name;
SQLite SELECT Statement:
SELECT column1, column2....columnN
FROM table_name;
SQLite UPDATE Statement:
UPDATE table_name
SET column1 = value1, column2 = value2....columnN=valueN
[ WHERE CONDITION ];
SQLite VACUUM Statement:
VACUUM;
SQLite WHERE Clause:
SELECT column1, column2....columnN
FROM table_name
WHERE CONDITION;](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-26-320.jpg)
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SQLite Insert Query
The SQLite INSERT INTO Statement is used to add new rows of data into a table in the database.
Syntax:
There are two basic syntaxes of INSERT INTO statement as follows:
INSERT INTO TABLE_NAME (column1, column2, column3,...columnN)]
VALUES (value1, value2, value3,...valueN);
Here, column1, column2,...columnN are the names of the columns in the table into which you want to insert data.
You may not need to specify the column(s) name in the SQLite query if you are adding values for all the columns
of the table. But make sure the order of the values is in the same order as the columns in the table. The SQLite
INSERT INTO syntax would be as follows:
INSERT INTO TABLE_NAME VALUES (value1,value2,value3,...valueN);
Example:
Consider you already have created COMPANY table in your testDB.db as follows:
sqlite> CREATE TABLE COMPANY(
ID INT PRIMARY KEY NOT NULL,
NAME TEXT NOT NULL,
AGE INT NOT NULL,
ADDRESS CHAR(50),
SALARY REAL
);
Now, following statements would create six records in COMPANY table:
INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (1, 'Paul', 32, 'California', 20000.00 );
INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (2, 'Allen', 25, 'Texas', 15000.00 );
INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );
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INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 );
INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (5, 'David', 27, 'Texas', 85000.00 );
INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (6, 'Kim', 22, 'South-Hall', 45000.00 );
You can create a record in COMPANY table using second syntax as follows:
INSERT INTO COMPANY VALUES (7, 'James', 24, 'Houston', 10000.00 );
All the above statements would create following records in COMPANY table. Next chapter will teach you how to
display all these records from a table.
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
Populate one table using another table:
You can populate data into a table through select statement over another table provided another table has a set
of fields, which are required to populate first table. Here is the syntax:
INSERT INTO first_table_name [(column1, column2, ... columnN)]
SELECT column1, column2, ...columnN
FROM second_table_name
[WHERE condition];
For now, you can skip above statement, first let's learn SELECT and WHERE clauses, which will be covered in
subsequent chapters.](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-38-320.jpg)
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SQLite Expressions
An expression is a combination of one or more values, operators and SQL functions that evaluate to a
value.
SQL EXPRESSIONs are like formulas and they are written in query language. You can also use to query the
database for specific set of data.
Syntax:
Consider the basic syntax of the SELECT statement as follows:
SELECT column1, column2, columnN
FROM table_name
WHERE [CONTION | EXPRESSION];
There are different types of SQLite expressions, which are mentioned below:
SQLite - Boolean Expressions:
SQLite Boolean Expressions fetch the data on the basis of matching single value. Following is the syntax:
SELECT column1, column2, columnN
FROM table_name
WHERE SINGLE VALUE MATCHTING EXPRESSION;
Consider COMPANY table has the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
Here is simple examples showing usage of SQLite Boolean Expressions:
sqlite> SELECT * FROM COMPANY WHERE SALARY = 10000;
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ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
4 James 24 Houston 10000.0
SQLite - Numeric Expression:
These expressions are used to perform any mathematical operation in any query. Following is the syntax:
SELECT numerical_expression as OPERATION_NAME
[FROM table_name WHERE CONDITION] ;
Here, numerical_expression is used for mathematical expression or any formula. Following is a simple example
showing usage of SQLite Numeric Expressions:
sqlite> SELECT (15 + 6) AS ADDITION
ADDITION = 21
There are several built-in functions like avg(), sum(), count(), etc., to perform what is known as aggregate data
calculations against a table or a specific table column.
sqlite> SELECT COUNT(*) AS "RECORDS" FROM COMPANY;
RECORDS = 7
SQLite - Date Expressions:
Date Expressions return current system date and time values and these expressions will be used in various data
manipulations.
sqlite> SELECT CURRENT_TIMESTAMP;
CURRENT_TIMESTAMP = 2013-03-17 10:43:35](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-51-320.jpg)
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SQLite Where Clause
The SQLite WHERE clause is used to specify a condition while fetching the data from one table or multiple
tables.
If the given condition is satisfied, means true, then it returns specific value from the table. You would use WHERE
clause to filter the records and fetching only necessary records.
The WHERE clause not only used in SELECT statement, but it is also used in UPDATE, DELETE statement, etc.,
which we would study in subsequent chapters.
Syntax:
The basic syntax of SQLite SELECT statement with WHERE clause is as follows:
SELECT column1, column2, columnN
FROM table_name
WHERE [condition]
Example:
You can specify a condition using Comparision or Logical Operators like >, <, =, LIKE, NOT, etc. Consider
COMPANY table has the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
Here are simple examples showing usage of SQLite Logical Operators. Following SELECT statement lists down
all the records where AGE is greater than or equal to 25 AND salary is greater than or equal to 65000.00:
sqlite> SELECT * FROM COMPANY WHERE AGE >= 25 AND SALARY >= 65000;
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
4 Mark 25 Rich-Mond 65000.0
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SQLite AND and OR Operator
The SQLite AND and OR operators are used to combine multiple conditions to narrow down selected data
in an SQLite statement. These two operators are called conjunctive operators.
These operators provide a means to make multiple comparisons with different operators in the same SQLite
statement.
The AND Operator:
The AND operator allows the existence of multiple conditions in an SQLite statement's WHERE clause. While
using AND operator, complete condition will be assumed true when all the conditions are true. For example,
[condition1] AND [condition2] will be true only when both condition1 and condition2 are true.
Syntax:
The basic syntax of AND operator with WHERE clause is as follows:
SELECT column1, column2, columnN
FROM table_name
WHERE [condition1] AND [condition2]...AND [conditionN];
You can combine N number of conditions using AND operator. For an action to be taken by the SQLite statement,
whether it be a transaction or query, all conditions separated by the AND must be TRUE.
Example:
Consider COMPANY table is having the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
Following SELECT statement lists down all the records where AGE is greater than or equal to 25 ANDsalary is
greater than or equal to 65000.00:
sqlite> SELECT * FROM COMPANY WHERE AGE >= 25 AND SALARY >= 65000;
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ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
The OR Operator:
The OR operator is also used to combine multiple conditions in an SQLite statement's WHERE clause. While
using OR operator, complete condition will be assumed true when at least any of the conditions is true. For
example, [condition1] OR [condition2] will be true if either condition1 or condition2 is true.
Syntax:
The basic syntax of OR operator with WHERE clause is as follows:
SELECT column1, column2, columnN
FROM table_name
WHERE [condition1] OR [condition2]...OR [conditionN]
You can combine N number of conditions using OR operator. For an action to be taken by the SQLite statement,
whether it be a transaction or query, only any ONE of the conditions separated by the OR must be TRUE.
Example:
Consider COMPANY table is having the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
Following SELECT statement lists down all the records where AGE is greater than or equal to 25 ORsalary is
greater than or equal to 65000.00:
sqlite> SELECT * FROM COMPANY WHERE AGE >= 25 OR SALARY >= 65000;
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-56-320.jpg)
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SQLite Update Query
The SQLite UPDATE Query is used to modify the existing records in a table. You can use WHERE clause
with UPDATE query to update selected rows, otherwise all the rows would be updated.
Syntax:
The basic syntax of UPDATE query with WHERE clause is as follows:
UPDATE table_name
SET column1 = value1, column2 = value2...., columnN = valueN
WHERE [condition];
You can combine N number of conditions using AND or OR operators.
Example:
Consider COMPANY table is having the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
Following is an example, which would update ADDRESS for a customer whose ID is 6:
sqlite> UPDATE COMPANY SET ADDRESS = 'Texas' WHERE ID = 6;
Now, COMPANY table would have the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
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SQLite Delete Query
The SQLite DELETE Query is used to delete the existing records from a table. You can use WHERE
clause with DELETE query to delete selected rows, otherwise all the records would be deleted.
Syntax:
The basic syntax of DELETE query with WHERE clause is as follows:
DELETE FROM table_name
WHERE [condition];
You can combine N number of conditions using AND or OR operators.
Example:
Consider COMPANY table is having the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
Following is an example, which would DELETE a customer whose ID is 7:
sqlite> DELETE FROM COMPANY WHERE ID = 7;
Now, COMPANY table will have the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
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SQLite LIMIT Clause
The SQLite LIMIT clause is used to limit the data amount returned by the SELECT statement.
Syntax:
The basic syntax of SELECT statement with LIMIT clause is as follows:
SELECT column1, column2, columnN
FROM table_name
LIMIT [no of rows]
Following is the syntax of LIMIT clause when it is used along with OFFSET clause:
SELECT column1, column2, columnN
FROM table_name
LIMIT [no of rows] OFFSET [row num]
SQLite engine will return rows starting from the next row to the given OFFSET as shown below in the last
example.
Example:
Consider COMPANY table is having the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
Following is an example, which limits the row in the table according to the number of rows you want to fetch from
table:
sqlite> SELECT * FROM COMPANY LIMIT 6;
This would produce the following result:
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SQLite Order By Clause
The SQLite ORDER BY clause is used to sort the data in ascending or descending order, based on one or
more columns.
Syntax:
The basic syntax of ORDER BY clause is as follows:
SELECT column-list
FROM table_name
[WHERE condition]
[ORDER BY column1, column2, .. columnN] [ASC | DESC];
You can use more than one column in the ORDER BY clause. Make sure whatever column you are using to sort,
that column should be available in column-list.
Example:
Consider COMPANY table is having the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
Following is an example, which would sort the result in descending order by SALARY:
sqlite> SELECT * FROM COMPANY ORDER BY SALARY ASC;
This would produce the following result:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
7 James 24 Houston 10000.0
2 Allen 25 Texas 15000.0
1 Paul 32 California 20000.0
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SQLite Group By Clause
The SQLite GROUP BY clause is used in collaboration with the SELECT statement to arrange identical
data into groups.
The GROUP BY clause follows the WHERE clause in a SELECT statement and precedes the ORDER BY clause.
Syntax:
The basic syntax of GROUP BY clause is given below. The GROUP BY clause must follow the conditions in the
WHERE clause and must precede the ORDER BY clause if one is used.
SELECT column-list
FROM table_name
WHERE [ conditions ]
GROUP BY column1, column2....columnN
ORDER BY column1, column2....columnN
You can use more than one column in the GROUP BY clause. Make sure whatever column you are using to
group, that column should be available in column-list.
Example:
Consider COMPANY table is having the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
If you want to know the total amount of salary on each customer, then GROUP BY query would be as follows:
sqlite> SELECT NAME, SUM(SALARY) FROM COMPANY GROUP BY NAME;
This would produce following result:
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SQLite Having Clause
The HAVING clause enables you to specify conditions that filter which group results appear in the final
results.
The WHERE clause places conditions on the selected columns, whereas the HAVING clause places conditions
on groups created by the GROUP BY clause.
Syntax:
The following is the position of the HAVING clause in a SELECT query:
SELECT
FROM
WHERE
GROUP BY
HAVING
ORDER BY
The HAVING clause must follow the GROUP BY clause in a query and must also precede the ORDER BY clause
if used. The following is the syntax of the SELECT statement, including the HAVING clause:
SELECT column1, column2
FROM table1, table2
WHERE [ conditions ]
GROUP BY column1, column2
HAVING [ conditions ]
ORDER BY column1, column2
Example:
Consider COMPANY table is having the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
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SQLite Distinct Keyword
The SQLite DISTINCT keyword is used in conjunction with SELECT statement to eliminate all the
duplicate records and fetching only unique records.
There may be a situation when you have multiple duplicate records in a table. While fetching such records, it
makes more sense to fetch only unique records instead of fetching duplicate records.
Syntax:
The basic syntax of DISTINCT keyword to eliminate duplicate records is as follows:
SELECT DISTINCT column1, column2,.....columnN
FROM table_name
WHERE [condition]
Example:
Consider COMPANY table is having the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
8 Paul 24 Houston 20000.0
9 James 44 Norway 5000.0
10 James 45 Texas 5000.0
First, let us see how the following SELECT query returns duplicate salary records:
sqlite> SELECT name FROM COMPANY;
This would produce the following result:
NAME
----------
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SQLite PRAGMA
The SQLite PRAGMA command is a special command to be used to control various environmental
variables and state flags within the SQLite environment. A PRAGMA value can be read and it can also be set
based on requirements.
Syntax:
To query the current PRAGMA value, just provide the name of the pragma:
PRAGMA pragma_name;
To set a new value for PRAGMA, you will use the following syntax:
PRAGMA pragma_name = value;
The set mode can be either the name or the integer equivalent but the returned value will always be an integer.
auto_vacuum Pragma
The auto_vacuum pragma gets or sets the auto-vacuum mode. Following is the simple syntax:
PRAGMA [database.]auto_vacuum;
PRAGMA [database.]auto_vacuum = mode;
Where mode can be any of the following:
Pragma Value Description
0 or NONE
Auto-vacuum is disabled. This is default mode which means that a database file will
never shrink in size unless it is manually vacuumed using the VACUUM command.
1 or FULL
Auto-vacuum is enabled and fully automatic which allows a database file to shrink as
data is removed from the database.
2 or INCREMENTAL
Auto-vacuum is enabled but must be manually activated. In this mode the reference
data is maintained, but free pages are simply put on the free list. These pages can be
recovered using the incremental_vacuum pragmaany time.
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cache_size Pragma
The cache_size pragma can get or temporarily set the maximum size of the in-memory page cache. Following is
the simple syntax:
PRAGMA [database.]cache_size;
PRAGMA [database.]cache_size = pages;
The pages value represents the number of pages in the cache. The built-in page cache has a default size of
2,000 pages and a minimum size of 10 pages.
case_sensitive_like Pragma
The case_sensitive_like pragma controls the case-sensitivity of the built-in LIKE expression. By default, this
pragma is false which means that the built-in LIKE operator ignores letter case. Following is the simple syntax:
PRAGMA case_sensitive_like = [true|false];
There is no way to query for the current state of this pragma.
count_changes Pragma
The count_changes pragma gets or sets the return value of data manipulation statements such as INSERT,
UPDATE and DELETE. Following is the simple syntax:
PRAGMA count_changes;
PRAGMA count_changes = [true|false];
By default, this pragma is false and these statements do not return anything. If set to true, each of the mentioned
statement will return an one-column, one-row table consisting of a single integer value indicating impacted rows
by the operation.
database_list Pragma
The database_list pragma will be used to list down all the databases attached. Following is the simple syntax:
PRAGMA database_list;
This pragma will return a three-column table with one row per open or attached database giving database
sequence number, its name and file associated.
encoding Pragma
The encoding pragma controls how strings are encoded and stored in a database file. Following is the simple
syntax:
PRAGMA encoding;
PRAGMA encoding = format;
The format value can be one of UTF-8, UTF-16le, or UTF-16be.
freelist_count Pragma
The freelist_count pragma returns a single integer indicating how many database pages are currently marked as
free and available. Following is the simple syntax:
PRAGMA [database.]freelist_count;](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-79-320.jpg)
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The format value can be one of UTF-8, UTF-16le, or UTF-16be.
index_info Pragma
The index_info pragma returns information about a database index. Following is the simple syntax:
PRAGMA [database.]index_info( index_name );
The result set will contain one row for each column contained in the index giving column sequence, column index
within table and column name.
index_list Pragma
The index_list pragma lists all of the indexes associated with a table. Following is the simple syntax:
PRAGMA [database.]index_list( table_name );
The result set will contain one row for each index giving index sequence, index name and flag indicating whether
index is unique or not.
journal_mode Pragma
The journal_mode pragma gets or sets the journal mode which controls how the journal file is stored and
processed. Following is the simple syntax:
PRAGMA journal_mode;
PRAGMA journal_mode = mode;
PRAGMA database.journal_mode;
PRAGMA database.journal_mode = mode;
There are five supported journal modes:
Pragma Value Description
DELETE This is default mode. Here at the conclusion of a transaction, the journal file is deleted.
TRUNCATE The journal file is truncated to a length of zero bytes.
PERSIST
The journal file is left in place, but the header is overwritten to indicate the journal is no
longer valid.
MEMORY The journal record is held in memory, rather than on disk.
OFF No journal record is kept.
max_page_count Pragma
The max_page_count pragma gets or sets the maximum allowed page count for a database. Following is the
simple syntax:
PRAGMA [database.]max_page_count;
PRAGMA [database.]max_page_count = max_page;
The default value is 1,073,741,823 which is one giga-page which means if the default 1 KB page size, this allows
databases to grow up to one terabyte.](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-80-320.jpg)
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page_count Pragma
The page_count pragma returns the current number of pages in database. Following is the simple syntax:
PRAGMA [database.]page_count;
The size of the database file should be page_count * page_size.
page_size Pragma
The page_size pragma gets or sets the size of the database pages. Following is the simple syntax:
PRAGMA [database.]page_size;
PRAGMA [database.]page_size = bytes;
By default, the allowed sizes are 512, 1024, 2048, 4096, 8192, 16384, and 32768 bytes. The only way to alter the
page size on an existing database is to set the page size and then immediately VACUUM the database.
parser_trace Pragma
The parser_trace pragma controls printing the debugging state as it parses SQL commands. Following is the
simple syntax:
PRAGMA parser_trace = [true|false];
By default, it is set to false but when enabled by setting it to true, the SQL parser will print its state as it parses
SQL commands.
recursive_triggers Pragma
The recursive_triggers pragma gets or sets the recursive trigger functionality. If recursive triggers are not
enabled, a trigger action will not fire another trigger. Following is the simple syntax:
PRAGMA recursive_triggers;
PRAGMA recursive_triggers = [true|false];
schema_version Pragma
The schema_version pragma gets or sets the schema version value that is stored in the database header.
Following is the simple syntax:
PRAGMA [database.]schema_version;
PRAGMA [database.]schema_version = number;
This is a 32-bit signed integer value that keeps track of schema changes. Whenever a schema-altering command
is executed (like, CREATE... or DROP...), this value is incremented.
secure_delete Pragma
The secure_delete pragma is used to control how content is deleted from the database. Following is the simple
syntax:
PRAGMA secure_delete;
PRAGMA secure_delete = [true|false];
PRAGMA database.secure_delete;
PRAGMA database.secure_delete = [true|false];](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-81-320.jpg)
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The default value for the secure delete flag is normally off, but this can be changed with the
SQLITE_SECURE_DELETE build option.
sql_trace Pragma
The sql_trace pragma is used to dump SQL trace results to the screen. Following is the simple syntax:
PRAGMA sql_trace;
PRAGMA sql_trace = [true|false];
SQLite must be compiled with the SQLITE_DEBUG directive for this pragma to be included.
synchronous Pragma
The synchronous pragma gets or sets the current disk synchronization mode which controls how aggressively
SQLite will write data all the way out to physical storage. Following is the simple syntax:
PRAGMA [database.]synchronous;
PRAGMA [database.]synchronous = mode;
SQLite supports the following synchronisation modes:
Pragma Value Description
0 or OFF No syncs at all
1 or NORMAL Sync after each sequence of critical disk operations
2 or FULL Sync after each critical disk operation
temp_store Pragma
The temp_store pragma gets or sets the storage mode used by temporary database files. Following is the simple
syntax:
PRAGMA temp_store;
PRAGMA temp_store = mode;
SQLite supports the following storage modes:
Pragma Value Description
0 or DEFAULT Use compile-time default. Normally FILE.
1 or FILE Use file-based storage.
2 or MEMORY Use memory-based storage.
temp_store_directory Pragma
The temp_store_directory pragma gets or sets the location used for temporary database files. Following is the
simple syntax:
PRAGMA temp_store_directory;
PRAGMA temp_store_directory = 'directory_path';](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-82-320.jpg)
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user_version Pragma
The user_version pragma gets or sets the user-defined version value that is stored in the database header.
Following is simple syntax:
PRAGMA [database.]user_version;
PRAGMA [database.]user_version = number;
This is a 32-bit signed integer value, which can be set by the developer for version tracking purpose.
writable_schema Pragma
The writable_schema pragma gets or sets the ability to modify system tables. Following is the simple syntax:
PRAGMA writable_schema;
PRAGMA writable_schema = [true|false];
If this pragma is set, tables that start with sqlite_ can be created and modified, including the sqlite_master table.
Be careful while using pragma because it can lead to complete database corruption.](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-83-320.jpg)
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An INNER JOIN is the most common type of join and is the default type of join. You can use INNER keyword
optionally.
Following is the syntax of INNER JOIN:
SELECT ... FROM table1 [INNER] JOIN table2 ON conditional_expression ...
To avoid redundancy and keep the phrasing shorter, INNER JOIN conditions can be declared with a
USING expression. This expression specifies a list of one or more columns:
SELECT ... FROM table1 JOIN table2 USING ( column1 ,... ) ...
A NATURAL JOIN is similar to a JOIN...USING, only it automatically tests for equality between the values of
every column that exists in both tables:
SELECT ... FROM table1 NATURAL JOIN table2...
Based on the above tables, we can write a INNER JOIN as follows:
sqlite> SELECT EMP_ID, NAME, DEPT FROM COMPANY INNER JOIN DEPARTMENT
ON COMPANY.ID = DEPARTMENT.EMP_ID;
Above query will produce the following result:
EMP_ID NAME DEPT
---------- ---------- ----------
1 Paul IT Billing
2 Allen Engineerin
7 James Finance
The OUTER JOIN
The OUTER JOIN is an extension of the INNER JOIN. Though SQL standard defines three types of OUTER
JOINs: LEFT, RIGHT and FULL but SQLite only supports the LEFT OUTER JOIN.
The OUTER JOINs have a condition that is identical to INNER JOINs, expressed using an ON, USING or
NATURAL keyword. The initial results table is calculated the same way. Once the primary JOIN is calculated, an
OUTER join will take any unjoined rows from one or both tables, pad them out with NULLs, and append them to
the resulting table.
Following is the syntax of LEFT OUTER JOIN:
SELECT ... FROM table1 LEFT OUTER JOIN table2 ON conditional_expression ...
To avoid redundancy and keep the phrasing shorter, OUTER JOIN conditions can be declared with a USING
expression. This expression specifies a list of one or more columns:
SELECT ... FROM table1 LEFT OUTER JOIN table2 USING ( column1 ,... ) ...
Based on the above tables, we can write a inner join as follows:
sqlite> SELECT EMP_ID, NAME, DEPT FROM COMPANY LEFT OUTER JOIN DEPARTMENT
ON COMPANY.ID = DEPARTMENT.EMP_ID;
Above query will produce the following result:
EMP_ID NAME DEPT
---------- ---------- ----------
1 Paul IT Billing
2 Allen Engineerin](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-89-320.jpg)
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SQLite UNIONS Clause
The SQLite UNION clause/operator is used to combine the results of two or more SELECT statements
without returning any duplicate rows.
To use UNION, each SELECT must have the same number of columns selected, the same number of column
expressions, the same data type, and have them in the same order, but they do not have to be the same length.
Syntax:
The basic syntax of UNION is as follows:
SELECT column1 [, column2 ]
FROM table1 [, table2 ]
[WHERE condition]
UNION
SELECT column1 [, column2 ]
FROM table1 [, table2 ]
[WHERE condition]
Here given condition could be any given expression based on your requirement.
Example:
The tables COMPANY and DEPARTMENT are shown here:
COMPANY TABLE
This is the file to create COMPANY table and to populate it with 7 records.
-- Just copy and past them on sqlite> prompt.
DROP TABLE COMPANY;
CREATE TABLE COMPANY(
ID INT PRIMARY KEY NOT NULL,
NAME TEXT NOT NULL,
AGE INT NOT NULL,
ADDRESS CHAR(50),
SALARY REAL
);
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6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
(b) Another table is DEPARTMENT as follows:
ID DEPT EMP_ID
---------- -------------------- ----------
1 IT Billing 1
2 Engineering 2
3 Finance 7
4 Engineering 3
5 Finance 4
6 Engineering 5
7 Finance 6
Now, let us join these two tables using SELECT statement along with UNION clause as follows:
sqlite> SELECT EMP_ID, NAME, DEPT FROM COMPANY INNER JOIN DEPARTMENT
ON COMPANY.ID = DEPARTMENT.EMP_ID
UNION
SELECT EMP_ID, NAME, DEPT FROM COMPANY LEFT OUTER JOIN DEPARTMENT
ON COMPANY.ID = DEPARTMENT.EMP_ID;
This would produce the following result:
EMP_ID NAME DEPT
---------- -------------------- ----------
1 Paul IT Billing
2 Allen Engineerin
3 Teddy Engineerin
4 Mark Finance
5 David Engineerin
6 Kim Finance
7 James Finance
The UNION ALL Clause:
The UNION ALL operator is used to combine the results of two SELECT statements including duplicate rows.
The same rules that apply to UNION apply to the UNION ALL operator as well.
Syntax:
The basic syntax of UNION ALL is as follows:
SELECT column1 [, column2 ]
FROM table1 [, table2 ]
[WHERE condition]
UNION ALL
SELECT column1 [, column2 ]
FROM table1 [, table2 ]
[WHERE condition]
Here given condition could be any given expression based on your requirement.](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-93-320.jpg)
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SQLite ALIAS Syntax
You can rename a table or a column temporarily by giving another name, which is known as ALIAS. The
use of table aliases means to rename a table in a particular SQLite statement. Renaming is a temporary change
and the actual table name does not change in the database.
The column aliases are used to rename a table's columns for the purpose of a particular SQLite query.
Syntax:
The basic syntax of table alias is as follows:
SELECT column1, column2....
FROM table_name AS alias_name
WHERE [condition];
The basic syntax of column alias is as follows:
SELECT column_name AS alias_name
FROM table_name
WHERE [condition];
Example:
Consider the following two tables, (a) COMPANY table is as follows:
sqlite> select * from COMPANY;
ID NAME AGE ADDRESS SALARY
---------- -------------------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
(b) Another table is DEPARTMENT as follows:
ID DEPT EMP_ID
---------- -------------------- ----------
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SQLite Triggers
SQLite Triggers are database callback functions, which are automatically performed/invoked when a
specified database event occurs. Following are the important points about SQLite triggers:
SQLite trigger may be specified to fire whenever a DELETE, INSERT or UPDATE of a particular database
table occurs or whenever an UPDATE occurs on on one or more specified columns of a table.
At this time, SQLite supports only FOR EACH ROW triggers, not FOR EACH STATEMENT triggers. Hence,
explicitly specifying FOR EACH ROW is optional.
Both the WHEN clause and the trigger actions may access elements of the row being inserted, deleted or
updated using references of the form NEW.column-name and OLD.column-name, where column-name is
the name of a column from the table that the trigger is associated with.
If a WHEN clause is supplied, the SQL statements specified are only executed for rows for which the WHEN
clause is true. If no WHEN clause is supplied, the SQL statements are executed for all rows.
The BEFORE or AFTER keyword determines when the trigger actions will be executed relative to the
insertion, modification or removal of the associated row.
Triggers are automatically dropped when the table that they are associated with is dropped.
The table to be modified must exist in the same database as the table or view to which the trigger is attached
and one must use just tablename not database.tablename.
A special SQL function RAISE() may be used within a trigger-program to raise an exception.
Syntax:
The basic syntax of creating a trigger is as follows:
CREATE TRIGGER trigger_name [BEFORE|AFTER] event_name
ON table_name
BEGIN
-- Trigger logic goes here....
END;
Here, event_name could be INSERT, DELETE, and UPDATE database operation on the mentioned
table table_name. You can optionally specify FOR EACH ROW after table name.
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Following is the syntax of creating a trigger on an UPDATE operation on one or more specified columns of a table
as follows:
CREATE TRIGGER trigger_name [BEFORE|AFTER] UPDATE OF column_name
ON table_name
BEGIN
-- Trigger logic goes here....
END;
Example
Let us consider a case where we want to keep audit trial for every record being inserted in COMPANY table,
which we create newly as follows (Drop COMPANY table if you already have it):
sqlite> CREATE TABLE COMPANY(
ID INT PRIMARY KEY NOT NULL,
NAME TEXT NOT NULL,
AGE INT NOT NULL,
ADDRESS CHAR(50),
SALARY REAL
);
To keep audit trial, we will create a new table called AUDIT where log messages will be inserted whenever there
is an entry in COMPANY table for a new record:
sqlite> CREATE TABLE AUDIT(
EMP_ID INT NOT NULL,
ENTRY_DATE TEXT NOT NULL
);
Here, ID is the AUDIT record ID, and EMP_ID is the ID which will come from COMPANY table and DATE will
keep timestamp when the record will be created in COMPANY table. So now let's create a trigger on COMPANY
table as follows:
sqlite> CREATE TRIGGER audit_log AFTER INSERT
ON COMPANY
BEGIN
INSERT INTO AUDIT(EMP_ID, ENTRY_DATE) VALUES (new.ID, datetime('now'));
END;
Now, we will start actual work, let's start inserting record in COMPANY table which should result in creating an
audit log record in AUDIT table. So let's create one record in COMPANY table as follows:
sqlite> INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (1, 'Paul', 32, 'California', 20000.00 );
This will create one record in COMPANY table, which is as follows:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
Same time, one record will be create in AUDIT table. This record is the result of a trigger, which we have created
on INSERT operation on COMPANY table. Similar way, you can create your triggers on UPDATE and DELETE
operations based on your requirements.
EMP_ID ENTRY_DATE
---------- -------------------
1 2013-04-05 06:26:00](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-100-320.jpg)
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SQLite Views
Aview is nothing more than a SQLite statement that is stored in the database with an associated name.
A view is actually a composition of a table in the form of a predefined SQLite query.
A view can contain all rows of a table or selected rows from one or more tables. A view can be created from one
or many tables which depends on the written SQLite query to create a view.
Views which are kind of virtual tables, allow users to do the following:
Structure data in a way that users or classes of users find natural or intuitive.
Restrict access to the data such that a user can only see limited data instead of complete table.
Summarize data from various tables which can be used to generate reports.
SQLite views are read-only and so you may not execute a DELETE, INSERT or UPDATE statement on a view.
But you can create a trigger on a view that fires on an attempt to DELETE, INSERT or UPDATE a view and do
what you need in the body of the trigger.
Creating Views:
The SQLite views are created using the CREATE VIEW statement. The SQLIte views can be created from a
single table, multiple tables, or another view.
The basic CREATE VIEW syntax is as follows:
CREATE [TEMP | TEMPORARY] VIEW view_name AS
SELECT column1, column2.....
FROM table_name
WHERE [condition];
You can include multiple tables in your SELECT statement in very similar way as you use them in normal SQL
SELECT query. If the optional TEMP or TEMPORARY keyword is present, the view will be created in the temp
database.
Example:
Consider COMPANY table is having the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
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SQLite Sub Queries
ASubquery or Inner query or Nested query is a query within another SQLite query and embedded within
the WHERE clause.
A subquery is used to return data that will be used in the main query as a condition to further restrict the data to
be retrieved.
Subqueries can be used with the SELECT, INSERT, UPDATE and DELETE statements along with the operators
like =, <, >, >=, <=, IN, BETWEEN etc.
There are a few rules that subqueries must follow:
Subqueries must be enclosed within parentheses.
A subquery can have only one column in the SELECT clause, unless multiple columns are in the main query
for the subquery to compare its selected columns.
An ORDER BY cannot be used in a subquery, although the main query can use an ORDER BY. The GROUP
BY can be used to perform the same function as the ORDER BY in a subquery.
Subqueries that return more than one row can only be used with multiple value operators, such as the IN
operator.
The BETWEEN operator cannot be used with a subquery; however, the BETWEEN can be used within the
subquery.
Subqueries with the SELECT Statement:
Subqueries are most frequently used with the SELECT statement. The basic syntax is as follows:
SELECT column_name [, column_name ]
FROM table1 [, table2 ]
WHERE column_name OPERATOR
(SELECT column_name [, column_name ]
FROM table1 [, table2 ]
[WHERE])
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Example:
Consider COMPANY table is having the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
Now, let us check following sub-query with SELECT statement:
sqlite> SELECT *
FROM COMPANY
WHERE ID IN (SELECT ID
FROM COMPANY
WHERE SALARY > 45000) ;
This would produce the following result:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
Subqueries with the INSERT Statement:
Subqueries also can be used with INSERT statements. The INSERT statement uses the data returned from the
subquery to insert into another table. The selected data in the subquery can be modified with any of the
character, date or number functions.
The basic syntax is as follows:
INSERT INTO table_name [ (column1 [, column2 ]) ]
SELECT [ *|column1 [, column2 ]
FROM table1 [, table2 ]
[ WHERE VALUE OPERATOR ]
Example:
Consider a table COMPANY_BKP with similar structure as COMPANY table and can be created using same
CREATE TABLE using COMPANY_BKP as table name. Now to copy complete COMPANY table into
COMPANY_BKP, following is the syntax:
sqlite> INSERT INTO COMPANY_BKP
SELECT * FROM COMPANY
WHERE ID IN (SELECT ID
FROM COMPANY) ;](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-116-320.jpg)
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Subqueries with the UPDATE Statement:
The subquery can be used in conjunction with the UPDATE statement. Either single or multiple columns in a table
can be updated when using a subquery with the UPDATE statement.
The basic syntax is as follows:
UPDATE table
SET column_name = new_value
[ WHERE OPERATOR [ VALUE ]
(SELECT COLUMN_NAME
FROM TABLE_NAME)
[ WHERE) ]
Example:
Assuming, we have COMPANY_BKP table available which is backup of COMPANY table.
Following example updates SALARY by 0.50 times in COMPANY table for all the customers, whose AGE is
greater than or equal to 27:
sqlite> UPDATE COMPANY
SET SALARY = SALARY * 0.50
WHERE AGE IN (SELECT AGE FROM COMPANY_BKP
WHERE AGE >= 27 );
This would impact two rows and finally COMPANY table would have the following records:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 10000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 42500.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
Subqueries with the DELETE Statement:
The subquery can be used in conjunction with the DELETE statement like with any other statements mentioned
above.
The basic syntax is as follows:
DELETE FROM TABLE_NAME
[ WHERE OPERATOR [ VALUE ]
(SELECT COLUMN_NAME
FROM TABLE_NAME)
[ WHERE) ]
Example:
Assuming, we have COMPANY_BKP table available which is backup of COMPANY table.](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-117-320.jpg)
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SQLite Injection
If you take user input through a webpage and insert it into a SQLite database, there's a chance that you have
left yourself wide open for a security issue known as SQL Injection. This lesson will teach you how to help prevent
this from happening and help you secure your scripts and SQLite statements.
Injection usually occurs when you ask a user for input, like their name, and instead of a name they give you a
SQLite statement that you will unknowingly run on your database.
Never trust user provided data, process this data only after validation; as a rule, this is done by pattern matching.
In the example below, the username is restricted to alphanumerical chars plus underscore and to a length
between 8 and 20 chars - modify these rules as needed.
if (preg_match("/^w{8,20}$/", $_GET['username'], $matches)){
$db = new SQLiteDatabase('filename');
$result = @$db->query("SELECT * FROM users WHERE username=$matches[0]");
}else{
echo "username not accepted";
}
To demonstrate the problem, consider this excerpt:
$name = "Qadir'; DELETE FROM users;";
@$db->query("SELECT * FROM users WHERE username='{$name}'");
The function call is supposed to retrieve a record from the users table where the name column matches the name
specified by the user. Under normal circumstances, $name would only contain alphanumeric characters and
perhaps spaces, such as the string ilia. But here, by appending an entirely new query to $name, the call to the
database turns into disaster: the injected DELETE query removes all records from users.
There are database's interfaces which do not permit query stacking or executing multiple queries in a single
function call. If you try to stack queries, the call fails but SQLite and PostgreSQL, happily perform stacked
queries, executing all of the queries provided in one string and creating a serious security problem.
Preventing SQL Injection:
You can handle all escape characters smartly in scripting languages like PERL and PHP. Programming language
PHP provides the function string sqlite_escape_string() to escape input characters that are special to SQLite.
if (get_magic_quotes_gpc())
{
$name = sqlite_escape_string($name);
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SQLite Explain
An SQLite statement can be preceded by the keyword "EXPLAIN" or by the phrase "EXPLAIN QUERY
PLAN" used for describing the details of table.
Either modification causes the SQLite statement to behave as a query and to return information about how the
SQLite statement would have operated if the EXPLAIN keyword or phrase had been omitted.
The output from EXPLAIN and EXPLAIN QUERY PLAN is intended for interactive analysis and
troubleshooting only.
The details of the output format are subject to change from one release of SQLite to the next.
Applications should not use EXPLAIN or EXPLAIN QUERY PLAN since their exact behavior is variable and
only partially documented.
Syntax:
Syntax for EXPLAIN is as follows:
EXPLAIN [SQLite Query]
Syntax for EXPLAIN QUERY PLAN is as follows:
EXPLAIN QUERY PLAN [SQLite Query]
Example:
This is the file to create COMPANY table and to populate it with 7 records.
-- Just copy and past them on sqlite> prompt.
DROP TABLE COMPANY;
CREATE TABLE COMPANY(
ID INT PRIMARY KEY NOT NULL,
NAME TEXT NOT NULL,
AGE INT NOT NULL,
ADDRESS CHAR(50),
SALARY REAL
);
INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
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statements associated with the connection should be finalized prior to closing the connection.
If any queries remain that have not been finalized, sqlite3_close() will return SQLITE_BUSY with the
error message Unable to close due to unfinalized statements.
Connecting To Database
Following C code segment shows how to connect to an existing database. If database does not exist, then it will
be created and finally a database object will be returned.
#include <stdio.h>
#include <sqlite3.h>
int main(int argc, char* argv[])
{
sqlite3 *db;
char *zErrMsg = 0;
int rc;
rc = sqlite3_open("test.db", &db);
if( rc ){
fprintf(stderr, "Can't open database: %sn", sqlite3_errmsg(db));
exit(0);
}else{
fprintf(stderr, "Opened database successfullyn");
}
sqlite3_close(db);
}
Now, let's compile and run above program to create our database test.db in the current directory. You can
change your path as per your requirement.
$gcc test.c -l sqlite3
$./a.out
Opened database successfully
If you are going to use C++ source code, then you can compile your code as follows:
$g++ test.c -l sqlite3
Here, we are linking our program with sqlite3 library to provide required functions to C program. This will create a
database file test.db in your directory and you will have the result something as follows:
-rwxr-xr-x. 1 root root 7383 May 8 02:06 a.out
-rw-r--r--. 1 root root 323 May 8 02:05 test.c
-rw-r--r--. 1 root root 0 May 8 02:06 test.db
Create a Table
Following C code segment will be used to create a table in previously created database:
#include <stdio.h>
#include <stdlib.h>
#include <sqlite3.h>
static int callback(void *NotUsed, int argc, char **argv, char **azColName){](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-137-320.jpg)
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int i;
for(i=0; i<argc; i++){
printf("%s = %sn", azColName[i], argv[i] ? argv[i] : "NULL");
}
printf("n");
return 0;
}
int main(int argc, char* argv[])
{
sqlite3 *db;
char *zErrMsg = 0;
int rc;
char *sql;
/* Open database */
rc = sqlite3_open("test.db", &db);
if( rc ){
fprintf(stderr, "Can't open database: %sn", sqlite3_errmsg(db));
exit(0);
}else{
fprintf(stdout, "Opened database successfullyn");
}
/* Create SQL statement */
sql = "CREATE TABLE COMPANY("
"ID INT PRIMARY KEY NOT NULL,"
"NAME TEXT NOT NULL,"
"AGE INT NOT NULL,"
"ADDRESS CHAR(50),"
"SALARY REAL );";
/* Execute SQL statement */
rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);
if( rc != SQLITE_OK ){
fprintf(stderr, "SQL error: %sn", zErrMsg);
sqlite3_free(zErrMsg);
}else{
fprintf(stdout, "Table created successfullyn");
}
sqlite3_close(db);
return 0;
}
When above program is compiled and executed, it will create COMPANY table in your test.db and final listing of
the file will be as follows:
-rwxr-xr-x. 1 root root 9567 May 8 02:31 a.out
-rw-r--r--. 1 root root 1207 May 8 02:31 test.c
-rw-r--r--. 1 root root 3072 May 8 02:31 test.db
INSERT Operation
Following C code segment shows how we can create records in our COMPANY table created in above example:
#include <stdio.h>
#include <stdlib.h>
#include <sqlite3.h>](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-138-320.jpg)
![TUTORIALS POINT
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static int callback(void *NotUsed, int argc, char **argv, char **azColName){
int i;
for(i=0; i<argc; i++){
printf("%s = %sn", azColName[i], argv[i] ? argv[i] : "NULL");
}
printf("n");
return 0;
}
int main(int argc, char* argv[])
{
sqlite3 *db;
char *zErrMsg = 0;
int rc;
char *sql;
/* Open database */
rc = sqlite3_open("test.db", &db);
if( rc ){
fprintf(stderr, "Can't open database: %sn", sqlite3_errmsg(db));
exit(0);
}else{
fprintf(stderr, "Opened database successfullyn");
}
/* Create SQL statement */
sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) "
"VALUES (1, 'Paul', 32, 'California', 20000.00 ); "
"INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) "
"VALUES (2, 'Allen', 25, 'Texas', 15000.00 ); "
"INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)"
"VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );"
"INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)"
"VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 );";
/* Execute SQL statement */
rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);
if( rc != SQLITE_OK ){
fprintf(stderr, "SQL error: %sn", zErrMsg);
sqlite3_free(zErrMsg);
}else{
fprintf(stdout, "Records created successfullyn");
}
sqlite3_close(db);
return 0;
}
When above program is compiled and executed, it will create given records in COMPANY table and will display
following two line:
Opened database successfully
Records created successfully
SELECT Operation
Before we proceed with actual example to fetch records, let me give a little detail about the callback function,
which we are using in our examples. This callback provides a way to obtain results from SELECT statements. It
has the following declaration:
typedef int (*sqlite3_callback)(](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-139-320.jpg)
![TUTORIALS POINT
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void*, /* Data provided in the 4th argument of sqlite3_exec() */
int, /* The number of columns in row */
char**, /* An array of strings representing fields in the row */
char** /* An array of strings representing column names */
);
If above callback is provided in sqlite_exec() routine as the third argument, SQLite will call the this callback
function for each record processed in each SELECT statement executed within the SQL argument.
Following C code segment shows how we can fetch and display records from our COMPANY table created in
above example:
#include <stdio.h>
#include <stdlib.h>
#include <sqlite3.h>
static int callback(void *data, int argc, char **argv, char **azColName){
int i;
fprintf(stderr, "%s: ", (const char*)data);
for(i=0; i<argc; i++){
printf("%s = %sn", azColName[i], argv[i] ? argv[i] : "NULL");
}
printf("n");
return 0;
}
int main(int argc, char* argv[])
{
sqlite3 *db;
char *zErrMsg = 0;
int rc;
char *sql;
const char* data = "Callback function called";
/* Open database */
rc = sqlite3_open("test.db", &db);
if( rc ){
fprintf(stderr, "Can't open database: %sn", sqlite3_errmsg(db));
exit(0);
}else{
fprintf(stderr, "Opened database successfullyn");
}
/* Create SQL statement */
sql = "SELECT * from COMPANY";
/* Execute SQL statement */
rc = sqlite3_exec(db, sql, callback, (void*)data, &zErrMsg);
if( rc != SQLITE_OK ){
fprintf(stderr, "SQL error: %sn", zErrMsg);
sqlite3_free(zErrMsg);
}else{
fprintf(stdout, "Operation done successfullyn");
}
sqlite3_close(db);
return 0;
}
When above program is compiled and executed, it will produce the following result:](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-140-320.jpg)
![TUTORIALS POINT
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Opened database successfully
Callback function called: ID = 1
NAME = Paul
AGE = 32
ADDRESS = California
SALARY = 20000.0
Callback function called: ID = 2
NAME = Allen
AGE = 25
ADDRESS = Texas
SALARY = 15000.0
Callback function called: ID = 3
NAME = Teddy
AGE = 23
ADDRESS = Norway
SALARY = 20000.0
Callback function called: ID = 4
NAME = Mark
AGE = 25
ADDRESS = Rich-Mond
SALARY = 65000.0
Operation done successfully
UPDATE Operation
Following C code segment shows how we can use UPDATE statement to update any record and then fetch and
display updated records from our COMPANY table:
#include <stdio.h>
#include <stdlib.h>
#include <sqlite3.h>
static int callback(void *data, int argc, char **argv, char **azColName){
int i;
fprintf(stderr, "%s: ", (const char*)data);
for(i=0; i<argc; i++){
printf("%s = %sn", azColName[i], argv[i] ? argv[i] : "NULL");
}
printf("n");
return 0;
}
int main(int argc, char* argv[])
{
sqlite3 *db;
char *zErrMsg = 0;
int rc;
char *sql;
const char* data = "Callback function called";
/* Open database */
rc = sqlite3_open("test.db", &db);
if( rc ){
fprintf(stderr, "Can't open database: %sn", sqlite3_errmsg(db));
exit(0);
}else{](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-141-320.jpg)
![TUTORIALS POINT
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for(i=0; i<argc; i++){
printf("%s = %sn", azColName[i], argv[i] ? argv[i] : "NULL");
}
printf("n");
return 0;
}
int main(int argc, char* argv[])
{
sqlite3 *db;
char *zErrMsg = 0;
int rc;
char *sql;
const char* data = "Callback function called";
/* Open database */
rc = sqlite3_open("test.db", &db);
if( rc ){
fprintf(stderr, "Can't open database: %sn", sqlite3_errmsg(db));
exit(0);
}else{
fprintf(stderr, "Opened database successfullyn");
}
/* Create merged SQL statement */
sql = "DELETE from COMPANY where ID=2; "
"SELECT * from COMPANY";
/* Execute SQL statement */
rc = sqlite3_exec(db, sql, callback, (void*)data, &zErrMsg);
if( rc != SQLITE_OK ){
fprintf(stderr, "SQL error: %sn", zErrMsg);
sqlite3_free(zErrMsg);
}else{
fprintf(stdout, "Operation done successfullyn");
}
sqlite3_close(db);
return 0;
}
When above program is compiled and executed, it will produce the following result:
Opened database successfully
Callback function called: ID = 1
NAME = Paul
AGE = 32
ADDRESS = California
SALARY = 20000.0
Callback function called: ID = 3
NAME = Teddy
AGE = 23
ADDRESS = Norway
SALARY = 20000.0
Callback function called: ID = 4
NAME = Mark
AGE = 25
ADDRESS = Rich-Mond
SALARY = 65000.0](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-143-320.jpg)
![TUTORIALS POINT
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SQLite Java Tutorial
Installation
Before we start using SQLite in our Java programs, we need to make sure that we have SQLite JDBC
Driver and Java set up on the machine. You can check Java tutorial for Java installation on your machine. Now,
let us check how to set up SQLite JDBC driver.
Download latest version of sqlite-jdbc-(VERSION).jar from sqlite-jdbc repository.
Add downloaded jar file sqlite-jdbc-(VERSION).jar in your class path, or you can use it along with -classpath
option as explained below in examples.
Following section assumes you have little knowledge about Java JDBC concepts. If you don't, then it is suggested
to spent half an hour with JDBC Tutorial to become comfortable with concepts explained below.
Connecting To Database
Following Java programs shows how to connect to an existing database. If database does not exist, then it will be
created and finally a database object will be returned.
import java.sql.*;
public class SQLiteJDBC
{
public static void main( String args[] )
{
Connection c = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:test.db");
} catch ( Exception e ) {
System.err.println( e.getClass().getName() + ": " + e.getMessage() );
System.exit(0);
}
System.out.println("Opened database successfully");
}
}
Now, let's compile and run above program to create our database test.db in the current directory. You can
change your path as per your requirement. We are assuming current version of JDBC driver sqlite-jdbc-3.7.2.jar is
available in the current path
CHAPTER
47](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-145-320.jpg)
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$javac SQLiteJDBC.java
$java -classpath ".:sqlite-jdbc-3.7.2.jar" SQLiteJDBC
Open database successfully
If you are going to use Windows machine, then you can compile and run your code as follows:
$javac SQLiteJDBC.java
$java -classpath ".;sqlite-jdbc-3.7.2.jar" SQLiteJDBC
Opened database successfully
Create a Table
Following Java program will be used to create a table in previously created database:
import java.sql.*;
public class SQLiteJDBC
{
public static void main( String args[] )
{
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:test.db");
System.out.println("Opened database successfully");
stmt = c.createStatement();
String sql = "CREATE TABLE COMPANY " +
"(ID INT PRIMARY KEY NOT NULL," +
" NAME TEXT NOT NULL, " +
" AGE INT NOT NULL, " +
" ADDRESS CHAR(50), " +
" SALARY REAL)";
stmt.executeUpdate(sql);
stmt.close();
c.close();
} catch ( Exception e ) {
System.err.println( e.getClass().getName() + ": " + e.getMessage() );
System.exit(0);
}
System.out.println("Table created successfully");
}
}
When above program is compiled and executed, it will create COMPANY table in your test.db and final listing of
the file will be as follows:
-rw-r--r--. 1 root root 3201128 Jan 22 19:04 sqlite-jdbc-3.7.2.jar
-rw-r--r--. 1 root root 1506 May 8 05:43 SQLiteJDBC.class
-rw-r--r--. 1 root root 832 May 8 05:42 SQLiteJDBC.java
-rw-r--r--. 1 root root 3072 May 8 05:43 test.db
INSERT Operation
Following Java program shows how we can create records in our COMPANY table created in above example:
import java.sql.*;](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-146-320.jpg)
![TUTORIALS POINT
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public class SQLiteJDBC
{
public static void main( String args[] )
{
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:test.db");
c.setAutoCommit(false);
System.out.println("Opened database successfully");
stmt = c.createStatement();
String sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " +
"VALUES (1, 'Paul', 32, 'California', 20000.00 );";
stmt.executeUpdate(sql);
sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " +
"VALUES (2, 'Allen', 25, 'Texas', 15000.00 );";
stmt.executeUpdate(sql);
sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " +
"VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );";
stmt.executeUpdate(sql);
sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " +
"VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 );";
stmt.executeUpdate(sql);
stmt.close();
c.commit();
c.close();
} catch ( Exception e ) {
System.err.println( e.getClass().getName() + ": " + e.getMessage() );
System.exit(0);
}
System.out.println("Records created successfully");
}
}
When above program is compiled and executed, it will create given records in COMPANY table and will display
following two line:
Opened database successfully
Records created successfully
SELECT Operation
Following Java program shows how we can fetch and display records from our COMPANY table created in above
example:
import java.sql.*;
public class SQLiteJDBC
{
public static void main( String args[] )
{
Connection c = null;
Statement stmt = null;](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-147-320.jpg)
![TUTORIALS POINT
Simply Easy Learning
UPDATE Operation
Following Java code shows how we can use UPDATE statement to update any record and then fetch and display
updated records from our COMPANY table:
import java.sql.*;
public class SQLiteJDBC
{
public static void main( String args[] )
{
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:test.db");
c.setAutoCommit(false);
System.out.println("Opened database successfully");
stmt = c.createStatement();
String sql = "UPDATE COMPANY set SALARY = 25000.00 where ID=1;";
stmt.executeUpdate(sql);
c.commit();
ResultSet rs = stmt.executeQuery( "SELECT * FROM COMPANY;" );
while ( rs.next() ) {
int id = rs.getInt("id");
String name = rs.getString("name");
int age = rs.getInt("age");
String address = rs.getString("address");
float salary = rs.getFloat("salary");
System.out.println( "ID = " + id );
System.out.println( "NAME = " + name );
System.out.println( "AGE = " + age );
System.out.println( "ADDRESS = " + address );
System.out.println( "SALARY = " + salary );
System.out.println();
}
rs.close();
stmt.close();
c.close();
} catch ( Exception e ) {
System.err.println( e.getClass().getName() + ": " + e.getMessage() );
System.exit(0);
}
System.out.println("Operation done successfully");
}
}
When above program is compiled and executed, it will produce the following result:
Opened database successfully
ID = 1
NAME = Paul
AGE = 32
ADDRESS = California
SALARY = 25000.0
ID = 2
NAME = Allen](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-149-320.jpg)
![TUTORIALS POINT
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AGE = 25
ADDRESS = Texas
SALARY = 15000.0
ID = 3
NAME = Teddy
AGE = 23
ADDRESS = Norway
SALARY = 20000.0
ID = 4
NAME = Mark
AGE = 25
ADDRESS = Rich-Mond
SALARY = 65000.0
Operation done successfully
DELETE Operation
Following Java code shows how we can use DELETE statement to delete any record and then fetch and display
remaining records from our COMPANY table:
import java.sql.*;
public class SQLiteJDBC
{
public static void main( String args[] )
{
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:test.db");
c.setAutoCommit(false);
System.out.println("Opened database successfully");
stmt = c.createStatement();
String sql = "DELETE from COMPANY where ID=2;";
stmt.executeUpdate(sql);
c.commit();
ResultSet rs = stmt.executeQuery( "SELECT * FROM COMPANY;" );
while ( rs.next() ) {
int id = rs.getInt("id");
String name = rs.getString("name");
int age = rs.getInt("age");
String address = rs.getString("address");
float salary = rs.getFloat("salary");
System.out.println( "ID = " + id );
System.out.println( "NAME = " + name );
System.out.println( "AGE = " + age );
System.out.println( "ADDRESS = " + address );
System.out.println( "SALARY = " + salary );
System.out.println();
}
rs.close();
stmt.close();
c.close();
} catch ( Exception e ) {](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-150-320.jpg)
![TUTORIALS POINT
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INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (1, 'Paul', 32, 'California', 20000.00 );
INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (2, 'Allen', 25, 'Texas', 15000.00 );
INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );
INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 );
EOF;
$ret = $db->exec($sql);
if(!$ret){
echo $db->lastErrorMsg();
} else {
echo "Records created successfullyn";
}
$db->close();
?>
When above program is executed, it will create given records in COMPANY table and will display the following
two lines:
Opened database successfully
Records created successfully
SELECT Operation
Following PHP program shows how we can fetch and display records from our COMPANY table created in above
example:
<?php
class MyDB extends SQLite3
{
function __construct()
{
$this->open('test.db');
}
}
$db = new MyDB();
if(!$db){
echo $db->lastErrorMsg();
} else {
echo "Opened database successfullyn";
}
$sql =<<<EOF
SELECT * from COMPANY;
EOF;
$ret = $db->query($sql);
while($row = $ret->fetchArray(SQLITE3_ASSOC) ){
echo "ID = ". $row['ID'] . "n";
echo "NAME = ". $row['NAME'] ."n";
echo "ADDRESS = ". $row['ADDRESS'] ."n";
echo "SALARY = ".$row['SALARY'] ."nn";
}
echo "Operation done successfullyn";](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-155-320.jpg)
![TUTORIALS POINT
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$ret = $db->query($sql);
while($row = $ret->fetchArray(SQLITE3_ASSOC) ){
echo "ID = ". $row['ID'] . "n";
echo "NAME = ". $row['NAME'] ."n";
echo "ADDRESS = ". $row['ADDRESS'] ."n";
echo "SALARY = ".$row['SALARY'] ."nn";
}
echo "Operation done successfullyn";
$db->close();
?>
When above program is executed, it will produce the following result:
Opened database successfully
1 Record updated successfully
ID = 1
NAME = Paul
ADDRESS = California
SALARY = 25000
ID = 2
NAME = Allen
ADDRESS = Texas
SALARY = 15000
ID = 3
NAME = Teddy
ADDRESS = Norway
SALARY = 20000
ID = 4
NAME = Mark
ADDRESS = Rich-Mond
SALARY = 65000
Operation done successfully
DELETE Operation
Following PHP code shows how we can use DELETE statement to delete any record and then fetch and display
remaining records from our COMPANY table:
<?php
class MyDB extends SQLite3
{
function __construct()
{
$this->open('test.db');
}
}
$db = new MyDB();
if(!$db){
echo $db->lastErrorMsg();
} else {
echo "Opened database successfullyn";
}
$sql =<<<EOF
DELETE from COMPANY where ID=2;
EOF;
$ret = $db->exec($sql);](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-157-320.jpg)
![TUTORIALS POINT
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if(!$ret){
echo $db->lastErrorMsg();
} else {
echo $db->changes(), " Record deleted successfullyn";
}
$sql =<<<EOF
SELECT * from COMPANY;
EOF;
$ret = $db->query($sql);
while($row = $ret->fetchArray(SQLITE3_ASSOC) ){
echo "ID = ". $row['ID'] . "n";
echo "NAME = ". $row['NAME'] ."n";
echo "ADDRESS = ". $row['ADDRESS'] ."n";
echo "SALARY = ".$row['SALARY'] ."nn";
}
echo "Operation done successfullyn";
$db->close();
?>
When above program is executed, it will produce the following result:
Opened database successfully
1 Record deleted successfully
ID = 1
NAME = Paul
ADDRESS = California
SALARY = 25000
ID = 3
NAME = Teddy
ADDRESS = Norway
SALARY = 20000
ID = 4
NAME = Mark
ADDRESS = Rich-Mond
SALARY = 65000
Operation done successfully](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-158-320.jpg)
![TUTORIALS POINT
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my $driver = "SQLite";
my $database = "test.db";
my $dsn = "DBI:$driver:dbname=$database";
my $userid = "";
my $password = "";
my $dbh = DBI->connect($dsn, $userid, $password, { RaiseError => 1 })
or die $DBI::errstr;
print "Opened database successfullyn";
my $stmt = qq(SELECT id, name, address, salary from COMPANY;);
my $sth = $dbh->prepare( $stmt );
my $rv = $sth->execute() or die $DBI::errstr;
if($rv < 0){
print $DBI::errstr;
}
while(my @row = $sth->fetchrow_array()) {
print "ID = ". $row[0] . "n";
print "NAME = ". $row[1] ."n";
print "ADDRESS = ". $row[2] ."n";
print "SALARY = ". $row[3] ."nn";
}
print "Operation done successfullyn";
$dbh->disconnect();
When above program is executed, it will produce the following result:
Opened database successfully
ID = 1
NAME = Paul
ADDRESS = California
SALARY = 20000
ID = 2
NAME = Allen
ADDRESS = Texas
SALARY = 15000
ID = 3
NAME = Teddy
ADDRESS = Norway
SALARY = 20000
ID = 4
NAME = Mark
ADDRESS = Rich-Mond
SALARY = 65000
Operation done successfully
UPDATE Operation
Following Perl code shows how we can use UPDATE statement to update any record and then fetch and display
updated records from our COMPANY table:
#!/usr/bin/perl
use DBI;
use strict;](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-163-320.jpg)
![TUTORIALS POINT
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my $driver = "SQLite";
my $database = "test.db";
my $dsn = "DBI:$driver:dbname=$database";
my $userid = "";
my $password = "";
my $dbh = DBI->connect($dsn, $userid, $password, { RaiseError => 1 })
or die $DBI::errstr;
print "Opened database successfullyn";
my $stmt = qq(UPDATE COMPANY set SALARY = 25000.00 where ID=1;);
my $rv = $dbh->do($stmt) or die $DBI::errstr;
if( $rv < 0 ){
print $DBI::errstr;
}else{
print "Total number of rows updated : $rvn";
}
$stmt = qq(SELECT id, name, address, salary from COMPANY;);
my $sth = $dbh->prepare( $stmt );
$rv = $sth->execute() or die $DBI::errstr;
if($rv < 0){
print $DBI::errstr;
}
while(my @row = $sth->fetchrow_array()) {
print "ID = ". $row[0] . "n";
print "NAME = ". $row[1] ."n";
print "ADDRESS = ". $row[2] ."n";
print "SALARY = ". $row[3] ."nn";
}
print "Operation done successfullyn";
$dbh->disconnect();
When above program is executed, it will produce the following result:
Opened database successfully
Total number of rows updated : 1
ID = 1
NAME = Paul
ADDRESS = California
SALARY = 25000
ID = 2
NAME = Allen
ADDRESS = Texas
SALARY = 15000
ID = 3
NAME = Teddy
ADDRESS = Norway
SALARY = 20000
ID = 4
NAME = Mark
ADDRESS = Rich-Mond
SALARY = 65000
Operation done successfully](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-164-320.jpg)
![TUTORIALS POINT
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DELETE Operation
Following Perl code shows how we can use DELETE statement to delete any record and then fetch and display
remaining records from our COMPANY table:
#!/usr/bin/perl
use DBI;
use strict;
my $driver = "SQLite";
my $database = "test.db";
my $dsn = "DBI:$driver:dbname=$database";
my $userid = "";
my $password = "";
my $dbh = DBI->connect($dsn, $userid, $password, { RaiseError => 1 })
or die $DBI::errstr;
print "Opened database successfullyn";
my $stmt = qq(DELETE from COMPANY where ID=2;);
my $rv = $dbh->do($stmt) or die $DBI::errstr;
if( $rv < 0 ){
print $DBI::errstr;
}else{
print "Total number of rows deleted : $rvn";
}
$stmt = qq(SELECT id, name, address, salary from COMPANY;);
my $sth = $dbh->prepare( $stmt );
$rv = $sth->execute() or die $DBI::errstr;
if($rv < 0){
print $DBI::errstr;
}
while(my @row = $sth->fetchrow_array()) {
print "ID = ". $row[0] . "n";
print "NAME = ". $row[1] ."n";
print "ADDRESS = ". $row[2] ."n";
print "SALARY = ". $row[3] ."nn";
}
print "Operation done successfullyn";
$dbh->disconnect();
When above program is executed, it will produce the following result:
Opened database successfully
Total number of rows deleted : 1
ID = 1
NAME = Paul
ADDRESS = California
SALARY = 25000
ID = 3
NAME = Teddy
ADDRESS = Norway
SALARY = 20000
ID = 4
NAME = Mark
ADDRESS = Rich-Mond
SALARY = 65000](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-165-320.jpg)
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SQLite Python
Installation
The SQLite3 can be integrated with Python using sqlite3 module, which was written by Gerhard Haring. It
provides an SQL interface compliant with the DB-API 2.0 specification described by PEP 249. You do not need to
install this module separately because its being shipped by default along with Python version 2.5.x onwards.
To use sqlite3 module, you must first create a connection object that represents the database and then optionally
you can create cursor object, which will help you in executing all the SQL statements.
Python sqlite3 module APIs
Following are important sqlite3 module routines, which can suffice your requirement to work with SQLite database
from your Perl program. If you are looking for a more sophisticated application, then you can look into Python
sqlite3 module's official documentation.
S.N. API & Description
1
sqlite3.connect(database [,timeout ,other optional arguments])
This API opens a connection to the SQLite database file database. You can use ":memory:" to open a
database connection to a database that resides in RAM instead of on disk. If database is opened
successfully, it returns a connection object.
When a database is accessed by multiple connections, and one of the processes modifies the database,
the SQLite database is locked until that transaction is committed. The timeout parameter specifies how
long the connection should wait for the lock to go away until raising an exception. The default for the
timeout parameter is 5.0 (five seconds).
If given database name does not exist then this call will create the database. You can specify filename
with required path as well if you want to create database anywhere else except in current directory.
2
connection.cursor([cursorClass])
This routine creates a cursor which will be used throughout of your database programming with Python.
This method accepts a single optional parameter cursorClass. If supplied, this must be a custom cursor
class that extends sqlite3.Cursor.
3 cursor.execute(sql [, optional parameters])
CHAPTER
50](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-166-320.jpg)
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This routine executes an SQL statement. The SQL statement may be parameterized (i. e. placeholders
instead of SQL literals). The sqlite3 module supports two kinds of placeholders: question marks and
named placeholders (named style).
For example:cursor.execute("insert into people values (?, ?)", (who, age))
4
connection.execute(sql [, optional parameters])
This routine is a shortcut of the above execute method provided by cursor object and it creates an
intermediate cursor object by calling the cursor method, then calls the cursor's execute method with the
parameters given.
5
cursor.executemany(sql, seq_of_parameters)
This routine executes an SQL command against all parameter sequences or mappings found in the
sequence sql.
6
connection.executemany(sql[, parameters])
This routine is a shortcut that creates an intermediate cursor object by calling the cursor method, then
calls the cursor.s executemany method with the parameters given.
7
cursor.executescript(sql_script)
This routine executes multiple SQL statements at once provided in the form of script. It issues a COMMIT
statement first, then executes the SQL script it gets as a parameter. All the SQL statements should be
separated by semi colon (;).
8
connection.executescript(sql_script)
This routine is a shortcut that creates an intermediate cursor object by calling the cursor method, then
calls the cursor's executescript method with the parameters given.
9
connection.total_changes()
This routine returns the total number of database rows that have been modified, inserted, or deleted
since the database connection was opened.
10
connection.commit()
This method commits the current transaction. If you don.t call this method, anything you did since the last
call to commit() is not visible from other database connections.
11
connection.rollback()
This method rolls back any changes to the database since the last call to commit().
12
connection.close()
This method closes the database connection. Note that this does not automatically call commit(). If you](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-167-320.jpg)
![TUTORIALS POINT
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just close your database connection without calling commit() first, your changes will be lost!
13
cursor.fetchone()
This method fetches the next row of a query result set, returning a single sequence, or None when no
more data is available.
14
cursor.fetchmany([size=cursor.arraysize])
This routine fetches the next set of rows of a query result, returning a list. An empty list is returned when
no more rows are available. The method tries to fetch as many rows as indicated by the size parameter.
15
cursor.fetchall()
This routine fetches all (remaining) rows of a query result, returning a list. An empty list is returned when
no rows are available.
Connecting To Database
Following Python code shows how to connect to an existing database. If database does not exist, then it will be
created and finally a database object will be returned.
#!/usr/bin/python
import sqlite3
conn = sqlite3.connect('test.db')
print "Opened database successfully";
Here, you can also supply database name as the special name :memory: to create a database in RAM. Now,
let's run above program to create our database test.db in the current directory. You can change your path as per
your requirement. Keep above code in sqlite.py file and execute it as shown below. If database is successfully
created, then it will give the following message:
$chmod +x sqlite.py
$./sqlite.py
Open database successfully
Create a Table
Following Python program will be used to create a table in previously created database:
#!/usr/bin/python
import sqlite3
conn = sqlite3.connect('test.db')
print "Opened database successfully";
conn.execute('''CREATE TABLE COMPANY
(ID INT PRIMARY KEY NOT NULL,
NAME TEXT NOT NULL,
AGE INT NOT NULL,](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-168-320.jpg)
![TUTORIALS POINT
Simply Easy Learning
print "ID = ", row[0]
print "NAME = ", row[1]
print "ADDRESS = ", row[2]
print "SALARY = ", row[3], "n"
print "Operation done successfully";
conn.close()
When above program is executed, it will produce the following result:
Opened database successfully
ID = 1
NAME = Paul
ADDRESS = California
SALARY = 20000.0
ID = 2
NAME = Allen
ADDRESS = Texas
SALARY = 15000.0
ID = 3
NAME = Teddy
ADDRESS = Norway
SALARY = 20000.0
ID = 4
NAME = Mark
ADDRESS = Rich-Mond
SALARY = 65000.0
Operation done successfully
UPDATE Operation
Following Python code shows how we can use UPDATE statement to update any record and then fetch and
display updated records from our COMPANY table:
#!/usr/bin/python
import sqlite3
conn = sqlite3.connect('test.db')
print "Opened database successfully";
conn.execute("UPDATE COMPANY set SALARY = 25000.00 where ID=1")
conn.commit
print "Total number of rows updated :", conn.total_changes
cursor = conn.execute("SELECT id, name, address, salary from COMPANY")
for row in cursor:
print "ID = ", row[0]
print "NAME = ", row[1]
print "ADDRESS = ", row[2]
print "SALARY = ", row[3], "n"
print "Operation done successfully";
conn.close()
When above program is executed, it will produce the following result:](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-170-320.jpg)
![TUTORIALS POINT
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Opened database successfully
Total number of rows updated : 1
ID = 1
NAME = Paul
ADDRESS = California
SALARY = 25000.0
ID = 2
NAME = Allen
ADDRESS = Texas
SALARY = 15000.0
ID = 3
NAME = Teddy
ADDRESS = Norway
SALARY = 20000.0
ID = 4
NAME = Mark
ADDRESS = Rich-Mond
SALARY = 65000.0
Operation done successfully
DELETE Operation
Following Python code shows how we can use DELETE statement to delete any record and then fetch and
display remaining records from our COMPANY table:
#!/usr/bin/python
import sqlite3
conn = sqlite3.connect('test.db')
print "Opened database successfully";
conn.execute("DELETE from COMPANY where ID=2;")
conn.commit
print "Total number of rows deleted :", conn.total_changes
cursor = conn.execute("SELECT id, name, address, salary from COMPANY")
for row in cursor:
print "ID = ", row[0]
print "NAME = ", row[1]
print "ADDRESS = ", row[2]
print "SALARY = ", row[3], "n"
print "Operation done successfully";
conn.close()
When above program is executed, it will produce the following result:
Opened database successfully
Total number of rows deleted : 1
ID = 1
NAME = Paul
ADDRESS = California
SALARY = 20000.0](https://image.slidesharecdn.com/sqlitetutorial-150925062029-lva1-app6892/85/Sqlite-tutorial-171-320.jpg)
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- 2. i SQLITE TUTORIAL Simply Easy Learning by tutorialspoint.com tutorialspoint.com
- 3. TUTORIALS POINT Simply Easy Learning ABOUT THE TUTORIAL SQLite Tutorial SQLite is a software library that implements a self-contained, serverless, zero-configuration, transactional SQL database engine. SQLite is the most widely deployed SQL database engine in the world. The source code for SQLite is in the public domain. This tutorial will give you quick start with SQLite and make you comfortable with SQLite programming. Audience This reference has been prepared for the beginners to help them understand the basic to advanced concepts related to SQLite Database Engine. Prerequisites Before you start doing practice with various types of examples given in this reference, I'm making an assumption that you are already aware about what is database, especially RDBMS and what is a computer programming language. Copyright & Disclaimer Notice All the content and graphics on this tutorial are the property of tutorialspoint.com. Any content from tutorialspoint.com or this tutorial may not be redistributed or reproduced in any way, shape, or form without the written permission of tutorialspoint.com. Failure to do so is a violation of copyright laws. This tutorial may contain inaccuracies or errors and tutorialspoint provides no guarantee regarding the accuracy of the site or its contents including this tutorial. If you discover that the tutorialspoint.com site or this tutorial content contains some errors, please contact us at [email protected]
- 4. TUTORIALS POINT Simply Easy Learning Table of Content SQLite Tutorial......................................................................... 2 Audience.................................................................................. 2 Prerequisites............................................................................ 2 Copyright & Disclaimer Notice.................................................. 2 SQLite Overview.................................................................... 12 What is SQLite? .......................................................................................12 Why SQLite?............................................................................................12 History:.....................................................................................................13 SQLite Limitations: ...................................................................................13 SQLite Commands:..................................................................................13 DDL - Data Definition Language: .............................................................13 DML - Data Manipulation Language:........................................................13 DQL - Data Query Language: ..................................................................14 SQLite Installation.................................................................. 15 Install SQLite On Windows.......................................................................15 Install SQLite On Linux.............................................................................15 Install SQLite On Mac OS X.....................................................................16 SQLite Commands................................................................. 17 Formatting output .....................................................................................19 The sqlite_master Table...........................................................................19 SQLite Syntax........................................................................ 20 Case Sensitivity........................................................................................20 Comments................................................................................................20 SQLite Statements ...................................................................................20 SQLite ANALYZE Statement:...................................................................20 SQLite AND/OR Clause: ..........................................................................21 SQLite ALTER TABLE Statement: ...........................................................21 SQLite ALTER TABLE Statement (Rename): ..........................................21 SQLite ATTACH DATABASE Statement:.................................................21 SQLite BEGIN TRANSACTION Statement: .............................................21 SQLite BETWEEN Clause: ......................................................................21 SQLite COMMIT Statement: ....................................................................21 SQLite CREATE INDEX Statement: ........................................................21 SQLite CREATE UNIQUE INDEX Statement:..........................................21 SQLite CREATE TABLE Statement: ........................................................22 SQLite CREATE TRIGGER Statement : ..................................................22 SQLite CREATE VIEW Statement : .........................................................22
- 5. TUTORIALS POINT Simply Easy Learning SQLite CREATE VIRTUAL TABLE Statement: ........................................22 SQLite COMMIT TRANSACTION Statement:..........................................22 SQLite COUNT Clause: ...........................................................................22 SQLite DELETE Statement:.....................................................................22 SQLite DETACH DATABASE Statement: ................................................23 SQLite DISTINCT Clause:........................................................................23 SQLite DROP INDEX Statement :............................................................23 SQLite DROP TABLE Statement: ............................................................23 SQLite DROP VIEW Statement : .............................................................23 SQLite DROP TRIGGER Statement : ......................................................23 SQLite EXISTS Clause: ...........................................................................23 SQLite EXPLAIN Statement :...................................................................23 SQLite GLOB Clause: ..............................................................................23 SQLite GROUP BY Clause: .....................................................................23 SQLite HAVING Clause: ..........................................................................24 SQLite INSERT INTO Statement: ............................................................24 SQLite IN Clause: ....................................................................................24 SQLite Like Clause: .................................................................................24 SQLite NOT IN Clause:............................................................................24 SQLite ORDER BY Clause: .....................................................................24 SQLite PRAGMA Statement: ...................................................................24 SQLite RELEASE SAVEPOINT Statement:.............................................25 SQLite REINDEX Statement:...................................................................25 SQLite ROLLBACK Statement:................................................................25 SQLite SAVEPOINT Statement: ..............................................................25 SQLite SELECT Statement:.....................................................................25 SQLite UPDATE Statement: ....................................................................25 SQLite VACUUM Statement: ...................................................................25 SQLite WHERE Clause:...........................................................................25 SQLite Data Type .................................................................. 26 SQLite Storage Classes:..........................................................................26 SQLite Affinity Type: ................................................................................26 SQLite Affinity and Type Names: .............................................................27 Boolean Datatype:....................................................................................28 Date and Time Datatype: .........................................................................28 SQLite Create Database........................................................ 29 Syntax: .....................................................................................................29 Example: ..................................................................................................29 The .dump Command...............................................................................30
- 6. TUTORIALS POINT Simply Easy Learning SQLite Attach Database......................................................... 31 Syntax: .....................................................................................................31 Example: ..................................................................................................31 SQLite Detach Database ....................................................... 32 Syntax: .....................................................................................................32 Example: ..................................................................................................32 SQLite Create Table .............................................................. 33 Syntax: .....................................................................................................33 Example: ..................................................................................................33 SQLite Drop Table ................................................................. 35 Syntax: .....................................................................................................35 Example: ..................................................................................................35 SQLite Insert Query ............................................................... 36 Syntax: .....................................................................................................36 Example: ..................................................................................................36 Populate one table using another table:...................................................37 SQLite Select Query .............................................................. 38 Syntax: .....................................................................................................38 Example: ..................................................................................................38 Setting output column width: ....................................................................39 Schema Information: ................................................................................39 SQLite Operators................................................................... 41 SQLite Arithmetic Operators: ...................................................................41 Example ...................................................................................................42 SQLite Comparison Operators:................................................................42 Example ...................................................................................................43 SQLite Logical Operators:........................................................................44 Example ...................................................................................................44 SQLite Bitwise Operators:........................................................................46 Example ...................................................................................................47 SQLite Expressions ............................................................... 49 Syntax: .....................................................................................................49 SQLite - Boolean Expressions: ................................................................49 SQLite - Numeric Expression:..................................................................50 SQLite - Date Expressions:......................................................................50 SQLite Where Clause ............................................................ 51 Syntax: .....................................................................................................51 Example: ..................................................................................................51 SQLite AND and OR Operator ............................................... 54
- 7. TUTORIALS POINT Simply Easy Learning The AND Operator: ..................................................................................54 Syntax: .....................................................................................................54 Example: ..................................................................................................54 The OR Operator: ....................................................................................55 Syntax: .....................................................................................................55 Example: ..................................................................................................55 SQLite Update Query............................................................. 56 Syntax: .....................................................................................................56 Example: ..................................................................................................56 SQLite Delete Query.............................................................. 58 Syntax: .....................................................................................................58 Example: ..................................................................................................58 SQLite Like Clause ................................................................ 60 Syntax: .....................................................................................................60 Example: ..................................................................................................61 SQLite Glob Clause ............................................................... 63 Syntax: .....................................................................................................63 Example: ..................................................................................................64 SQLite LIMIT Clause.............................................................. 66 Syntax: .....................................................................................................66 Example: ..................................................................................................66 SQLite Order By Clause......................................................... 68 Syntax: .....................................................................................................68 Example: ..................................................................................................68 SQLite Group By Clause........................................................ 70 Syntax: .....................................................................................................70 Example: ..................................................................................................70 SQLite Having Clause............................................................ 73 Syntax: .....................................................................................................73 Example: ..................................................................................................73 SQLite Distinct Keyword ........................................................ 75 Syntax: .....................................................................................................75 Example: ..................................................................................................75 SQLite PRAGMA ................................................................... 77 Syntax: .....................................................................................................77 auto_vacuum Pragma ..............................................................................77 cache_size Pragma..................................................................................78 case_sensitive_like Pragma.....................................................................78 count_changes Pragma ...........................................................................78
- 8. TUTORIALS POINT Simply Easy Learning database_list Pragma...............................................................................78 encoding Pragma.....................................................................................78 freelist_count Pragma ..............................................................................78 index_info Pragma ...................................................................................79 index_list Pragma.....................................................................................79 journal_mode Pragma..............................................................................79 max_page_count Pragma ........................................................................79 page_count Pragma.................................................................................80 page_size Pragma ...................................................................................80 parser_trace Pragma................................................................................80 recursive_triggers Pragma .......................................................................80 schema_version Pragma..........................................................................80 secure_delete Pragma .............................................................................80 sql_trace Pragma.....................................................................................81 synchronous Pragma ...............................................................................81 temp_store Pragma..................................................................................81 temp_store_directory Pragma..................................................................81 user_version Pragma ...............................................................................82 writable_schema Pragma.........................................................................82 SQLite Constraints................................................................. 83 NOT NULL Constraint ..............................................................................83 EXAMPLE: ...............................................................................................83 DEFAULT Constraint................................................................................83 EXAMPLE: ...............................................................................................84 UNIQUE Constraint..................................................................................84 EXAMPLE: ...............................................................................................84 PRIMARY KEY Constraint .......................................................................84 EXAMPLE: ...............................................................................................84 CHECK Constraint ...................................................................................85 EXAMPLE: ...............................................................................................85 Dropping Constraints:...............................................................................85 SQLite Joins .......................................................................... 86 The CROSS JOIN ....................................................................................87 The INNER JOIN......................................................................................87 The OUTER JOIN ....................................................................................88 SQLite UNIONS Clause......................................................... 90 Syntax: .....................................................................................................90 Example: ..................................................................................................90 COMPANY TABLE...................................................................................90
- 9. TUTORIALS POINT Simply Easy Learning The UNION ALL Clause:..........................................................................92 Syntax: .....................................................................................................92 Example: ..................................................................................................93 SQLite NULL Values.............................................................. 94 Syntax: .....................................................................................................94 Example: ..................................................................................................94 SQLite ALIAS Syntax............................................................. 96 Syntax: .....................................................................................................96 Example: ..................................................................................................96 SQLite Triggers...................................................................... 98 Syntax: .....................................................................................................98 Example ...................................................................................................99 Listing TRIGGERS .................................................................................100 Dropping TRIGGERS.............................................................................100 SQLite Indexes .................................................................... 101 The CREATE INDEX Command: ...........................................................101 Single-Column Indexes: .........................................................................101 Unique Indexes: .....................................................................................101 Composite Indexes: ...............................................................................102 Implicit Indexes: .....................................................................................102 Example .................................................................................................102 The DROP INDEX Command: ...............................................................102 When should indexes be avoided? ........................................................103 SQLite Indexed By............................................................... 104 Syntax ....................................................................................................104 Example .................................................................................................104 SQLite Alter Command ........................................................ 106 Syntax: ...................................................................................................106 Example: ................................................................................................106 SQLite Truncate Table......................................................... 108 Syntax: ...................................................................................................108 Example: ................................................................................................108 SQLite Views ....................................................................... 109 Creating Views: ......................................................................................109 Example: ................................................................................................109 Dropping Views: .....................................................................................110 SQLite TRANSACTIONS..................................................... 111 Properties of Transactions: ....................................................................111 Transaction Control:...............................................................................111
- 10. TUTORIALS POINT Simply Easy Learning The BEGIN TRANSACTION Command:................................................112 The COMMIT Command:.......................................................................112 The ROLLBACK Command: ..................................................................112 Example: ................................................................................................112 SQLite Sub Queries ............................................................. 114 Subqueries with the SELECT Statement:...............................................114 Example: ................................................................................................115 Subqueries with the INSERT Statement: ...............................................115 Example: ................................................................................................115 Subqueries with the UPDATE Statement:..............................................116 Example: ................................................................................................116 Subqueries with the DELETE Statement:...............................................116 Example: ................................................................................................116 SQLite AUTOINCREMENT.................................................. 118 Syntax: ...................................................................................................118 Example: ................................................................................................118 SQLite Injection.................................................................... 120 Preventing SQL Injection:.......................................................................120 SQLite Explain ..................................................................... 122 Syntax: ...................................................................................................122 Example: ................................................................................................122 SQLite Vacuum.................................................................... 125 Manual VACUUM...................................................................................125 Auto-VACCUM.......................................................................................125 SQLite Date & Time ............................................................. 127 Time Strings:..........................................................................................127 Modifiers.................................................................................................128 Formatters:.............................................................................................128 Examples ...............................................................................................129 SQLite Useful Functions ...................................................... 131 SQLite COUNT Function........................................................................132 SQLite MAX Function.............................................................................132 SQLite MIN Function..............................................................................132 SQLite AVG Function.............................................................................132 SQLite SUM Function.............................................................................133 SQLite RANDOM Function.....................................................................133 SQLite ABS Function .............................................................................133 SQLite UPPER Function ........................................................................133 SQLite LOWER Function .......................................................................134
- 11. TUTORIALS POINT Simply Easy Learning SQLite LENGTH Function......................................................................134 SQLite sqlite_version Function...............................................................134 SQLite C/C++ Tutorial.......................................................... 135 C/C++ Interface APIs .............................................................................135 Connecting To Database........................................................................136 Create a Table .......................................................................................136 INSERT Operation .................................................................................137 SELECT Operation ................................................................................138 UPDATE Operation................................................................................140 DELETE Operation ................................................................................141 SQLite Java Tutorial ............................................................ 144 Connecting To Database........................................................................144 Create a Table .......................................................................................145 INSERT Operation .................................................................................145 SELECT Operation ................................................................................146 UPDATE Operation................................................................................148 DELETE Operation ................................................................................149 SQLite PHP Tutorial............................................................. 151 PHP Interface APIs ................................................................................151 Connecting To Database........................................................................152 Create a Table .......................................................................................152 INSERT Operation .................................................................................153 SELECT Operation ................................................................................154 UPDATE Operation................................................................................155 DELETE Operation ................................................................................156 SQLite Perl Tutorial.............................................................. 158 DBI Interface APIs..................................................................................158 Connecting To Database........................................................................159 Create a Table .......................................................................................160 INSERT Operation .................................................................................161 SELECT Operation ................................................................................161 UPDATE Operation................................................................................162 DELETE Operation ................................................................................164 SQLite Python...................................................................... 165 Python sqlite3 module APIs ...................................................................165 Connecting To Database........................................................................167 Create a Table .......................................................................................167 INSERT Operation .................................................................................168 SELECT Operation ................................................................................168
- 12. TUTORIALS POINT Simply Easy Learning UPDATE Operation................................................................................169 DELETE Operation ................................................................................170
- 13. TUTORIALS POINT Simply Easy Learning SQLite Overview Tthis tutorial helps you to understand what is SQLite , how it differs from SQL, why it is needed and the way in which it handles the applications Database. SQLite is a software library that implements a self-contained, serverless, zero-configuration, transactional SQL database engine. SQLite is one of the fastest-growing database engines around, but that's growth in terms of popularity, not anything to do with its size. The source code for SQLite is in the public domain. What is SQLite? SQLite is an in-process library that implements a self-contained, serverless, zero-configuration, transactional SQL database engine. It is the one database, which is zero-configured, that means like other database you do not need to configure it in your system. SQLite engine is not a standalone process like other databases, you can link it statically or dynamically as per your requirement with your application. The SQLite accesses its storage files directly. Why SQLite? SQLite does not require a separate server process or system to operate (serverless). SQLite comes with zero-configuration, which means no setup or administration needed. A complete SQLite database is stored in a single cross-platform disk file. SQLite is very small and light weight, less than 400KiB fully configured or less than 250KiB with optional features omitted. SQLite is self-contained, which means no external dependencies. SQLite transactions are fully ACID-compliant, allowing safe access from multiple processes or threads. SQLite supports most of the query language features found in the SQL92 (SQL2) standard. SQLite is written in ANSI-C and provides simple and easy-to-use API. SQLite is available on UNIX (Linux, Mac OS-X, Android, iOS) and Windows (Win32, WinCE, WinRT). CHAPTER 1
- 14. TUTORIALS POINT Simply Easy Learning History: 1. 2000 -- D. Richard Hipp had designed SQLite for the purpose of no administration required for operating a program. 2. 2000 -- In August, SQLite 1.0 released with GNU Database Manager. 3. 2011 -- Hipp announced to add UNQl interface to SQLite DB and to develop UNQLite (Document oriented database). SQLite Limitations: There are few unsupported features of SQL92 in SQLite which are shown below: Feature Description RIGHT OUTER JOIN Only LEFT OUTER JOIN is implemented. FULL OUTER JOIN Only LEFT OUTER JOIN is implemented. ALTER TABLE The RENAME TABLE and ADD COLUMN variants of the ALTER TABLE command are supported. The DROP COLUMN, ALTER COLUMN, ADD CONSTRAINT not supported. Trigger support FOR EACH ROW triggers are supported but not FOR EACH STATEMENT triggers. VIEWs VIEWs in SQLite are read-only. You may not execute a DELETE, INSERT, or UPDATE statement on a view. GRANT and REVOKE The only access permissions that can be applied are the normal file access permissions of the underlying operating system. SQLite Commands: The standard SQLite commands to interact with relational databases are similar as SQL. They are CREATE, SELECT, INSERT, UPDATE, DELETE and DROP. These commands can be classified into groups based on their operational nature: DDL - Data Definition Language: Command Description CREATE Creates a new table, a view of a table, or other object in database ALTER Modifies an existing database object, such as a table. DROP Deletes an entire table, a view of a table or other object in the database. DML - Data Manipulation Language: Command Description INSERT Creates a record UPDATE Modifies records
- 15. TUTORIALS POINT Simply Easy Learning DELETE Deletes records DQL - Data Query Language: Command Description SELECT Retrieves certain records from one or more tables
- 16. TUTORIALS POINT Simply Easy Learning SQLite Installation The SQLite is famous for its great feature zero-configuration, which means no complex setup or administration is needed. This chapter will take you through the process of setting up SQLite on Windows, Linux and Mac OS X. Install SQLite On Windows Go to SQLite download page, and download precompiled binaries from Windows section. You will need to download sqlite-shell-win32-*.zip and sqlite-dll-win32-*.zip zipped files. Create a folder C:>sqlite and unzip above two zipped files in this folder which will give you sqlite3.def, sqlite3.dll and sqlite3.exe files. Add C:>sqlite in your PATH environment variable and finally go to the command prompt and issue sqlite3 command, which should display a result something as below. C:>sqlite3 SQLite version 3.7.15.2 2013-01-09 11:53:05 Enter ".help" for instructions Enter SQL statements terminated with a ";" sqlite> Install SQLite On Linux Today, almost all the flavours of Linux OS are being shipped with SQLite. So you just issue the following command to check if you already have SQLite installed on your machine or not. $sqlite3 SQLite version 3.7.15.2 2013-01-09 11:53:05 Enter ".help" for instructions Enter SQL statements terminated with a ";" sqlite> If you do not see above result, then it means you do not have SQLite installed on your Linux machine. So let's follow the following steps to install SQLite: Go to SQLite download page and download sqlite-autoconf-*.tar.gz from source code section. Follow the following steps: CHAPTER 2
- 17. TUTORIALS POINT Simply Easy Learning $tar xvfz sqlite-autoconf-3071502.tar.gz $cd sqlite-autoconf-3071502 $./configure --prefix=/usr/local $make $make install Above procedure will end with SQLite installation on your Linux machine which you can verify as explained above. Install SQLite On Mac OS X Though latest version of Mac OS X comes pre-installed with SQLite but if you do not have installation available then just follow the following steps: Go to SQLite download page and download sqlite-autoconf-*.tar.gz from source code section. Follow the following steps: $tar xvfz sqlite-autoconf-3071502.tar.gz $cd sqlite-autoconf-3071502 $./configure --prefix=/usr/local $make $make install Above procedure will end with SQLite installation on your Mac OS X machine which you can verify by issuing following command: $sqlite3 SQLite version 3.7.15.2 2013-01-09 11:53:05 Enter ".help" for instructions Enter SQL statements terminated with a ";" sqlite> Finally, you have SQLite command prompt where you can issue SQLite commands to do your excercises.
- 18. TUTORIALS POINT Simply Easy Learning SQLite Commands This chapter will take you through simple and useful commands used by SQLite programmers. These commands are called SQLite dot commands and exception with these commands is that they should not be terminated by a semi-colon (;). Let's start with typing a simple sqlite3 command at command prompt which will provide you SQLite command prompt where you will issue various SQLite commands. $sqlite3 SQLite version 3.3.6 Enter ".help" for instructions sqlite> For a listing of the available dot commands, you can enter ".help" at any time. For example: sqlite>.help Above command will display a list of various important SQLite dot commands, which are as follows: Command Description .backup ?DB? FILE Backup DB (default "main") to FILE .bail ON|OFF Stop after hitting an error. Default OFF .databases List names and files of attached databases .dump ?TABLE? Dump the database in an SQL text format. If TABLE specified, only dump tables matching LIKE pattern TABLE. .echo ON|OFF Turn command echo on or off .exit Exit SQLite prompt .explain ON|OFF Turn output mode suitable for EXPLAIN on or off. With no args, it turns EXPLAIN on. .header(s) ON|OFF Turn display of headers on or off .help Show this message .import FILE TABLE Import data from FILE into TABLE .indices ?TABLE? Show names of all indices. If TABLE specified, only show indices for tables matching CHAPTER 3
- 19. TUTORIALS POINT Simply Easy Learning LIKE pattern TABLE. .load FILE ?ENTRY? Load an extension library .log FILE|off Turn logging on or off. FILE can be stderr/stdout .mode MODE Set output mode where MODE is one of: csv Comma-separated values column Left-aligned columns. html HTML <table> code insert SQL insert statements for TABLE line One value per line list Values delimited by .separator string tabs Tab-separated values tcl TCL list elements .nullvalue STRING Print STRING in place of NULL values .output FILENAME Send output to FILENAME .output stdout Send output to the screen .print STRING... Print literal STRING .prompt MAIN CONTINUE Replace the standard prompts .quit Exit SQLite prompt .read FILENAME Execute SQL in FILENAME .schema ?TABLE? Show the CREATE statements. If TABLE specified, only show tables matching LIKE pattern TABLE. .separator STRING Change separator used by output mode and .import .show Show the current values for various settings .stats ON|OFF Turn stats on or off .tables ?PATTERN? List names of tables matching a LIKE pattern .timeout MS Try opening locked tables for MS milliseconds .width NUM NUM Set column widths for "column" mode .timer ON|OFF Turn the CPU timer measurement on or off Let's try .show command to see default setting for your SQLite command prompt. sqlite>.show echo: off explain: off headers: off mode: column nullvalue: "" output: stdout separator: "|" width: sqlite>
- 20. TUTORIALS POINT Simply Easy Learning Make sure there is no space in between sqlite> prompt and dot command, otherwise it will not work. Formatting output You can use the following sequence of dot commands to format your output the way I have listed down in this tutorial: sqlite>.header on sqlite>.mode column sqlite>.timer on sqlite> Above setting will produce the output in the following format: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 CPU Time: user 0.000000 sys 0.000000 The sqlite_master Table The master table holds the key information about your database tables and it is called sqlite_master. You can see its schema as follows: sqlite>.schema sqlite_master This will produce the following result: CREATE TABLE sqlite_master ( type text, name text, tbl_name text, rootpage integer, sql text );
- 21. TUTORIALS POINT Simply Easy Learning SQLite Syntax SQLite is followed by unique set of rules and guidelines called Syntax. This tutorial gives you a quick start with SQLite by listing all the basic SQLite Syntax. Case Sensitivity Important point to be noted is that SQLite is case insensitive, but there are some commands, which are case sensitive like GLOB and glob have different meaning in SQLite statements. Comments SQLite comments are extra notes, which you can add in your SQLite code to increase its readability and they can appear anywhere; whitespace can occur, including inside expressions and in the middle of other SQL statements but they can not be nested. SQL comments begin with two consecutive "-" characters (ASCII 0x2d) and extend up to and including the next newline character (ASCII 0x0a) or until the end of input, whichever comes first. You can also use C-style comments, which begin with "/*" and extend up to and including the next "*/" character pair or until the end of input, whichever comes first. C-style comments can span multiple lines. sqlite>.help -- This is a single line comment SQLite Statements All the SQLite statements start with any of the keywords like SELECT, INSERT, UPDATE, DELETE, ALTER, DROP, etc., and all the statements end with a semicolon (;). SQLite ANALYZE Statement: ANALYZE; or ANALYZE database_name; or ANALYZE database_name.table_name; CHAPTER 4
- 22. TUTORIALS POINT Simply Easy Learning SQLite AND/OR Clause: SELECT column1, column2....columnN FROM table_name WHERE CONDITION-1 {AND|OR} CONDITION-2; SQLite ALTER TABLE Statement: ALTER TABLE table_name ADD COLUMN column_def...; SQLite ALTER TABLE Statement (Rename): ALTER TABLE table_name RENAME TO new_table_name; SQLite ATTACH DATABASE Statement: ATTACH DATABASE 'DatabaseName' As 'Alias-Name'; SQLite BEGIN TRANSACTION Statement: BEGIN; or BEGIN EXCLUSIVE TRANSACTION; SQLite BETWEEN Clause: SELECT column1, column2....columnN FROM table_name WHERE column_name BETWEEN val-1 AND val-2; SQLite COMMIT Statement: COMMIT; SQLite CREATE INDEX Statement: CREATE INDEX index_name ON table_name ( column_name COLLATE NOCASE ); SQLite CREATE UNIQUE INDEX Statement: CREATE UNIQUE INDEX index_name ON table_name ( column1, column2,...columnN);
- 23. TUTORIALS POINT Simply Easy Learning SQLite CREATE TABLE Statement: CREATE TABLE table_name( column1 datatype, column2 datatype, column3 datatype, ..... columnN datatype, PRIMARY KEY( one or more columns ) ); SQLite CREATE TRIGGER Statement : CREATE TRIGGER database_name.trigger_name BEFORE INSERT ON table_name FOR EACH ROW BEGIN stmt1; stmt2; .... END; SQLite CREATE VIEW Statement : CREATE VIEW database_name.view_name AS SELECT statement....; SQLite CREATE VIRTUAL TABLE Statement: CREATE VIRTUAL TABLE database_name.table_name USING weblog( access.log ); or CREATE VIRTUAL TABLE database_name.table_name USING fts3( ); SQLite COMMIT TRANSACTION Statement: COMMIT; SQLite COUNT Clause: SELECT COUNT(column_name) FROM table_name WHERE CONDITION; SQLite DELETE Statement: DELETE FROM table_name WHERE {CONDITION};
- 24. TUTORIALS POINT Simply Easy Learning SQLite DETACH DATABASE Statement: DETACH DATABASE 'Alias-Name'; SQLite DISTINCT Clause: SELECT DISTINCT column1, column2....columnN FROM table_name; SQLite DROP INDEX Statement : DROP INDEX database_name.index_name; SQLite DROP TABLE Statement: DROP TABLE database_name.table_name; SQLite DROP VIEW Statement : DROP INDEX database_name.view_name; SQLite DROP TRIGGER Statement : DROP INDEX database_name.trigger_name; SQLite EXISTS Clause: SELECT column1, column2....columnN FROM table_name WHERE column_name EXISTS (SELECT * FROM table_name ); SQLite EXPLAIN Statement : EXPLAIN INSERT statement...; or EXPLAIN QUERY PLAN SELECT statement...; SQLite GLOB Clause: SELECT column1, column2....columnN FROM table_name WHERE column_name GLOB { PATTERN }; SQLite GROUP BY Clause: SELECT SUM(column_name)
- 25. TUTORIALS POINT Simply Easy Learning FROM table_name WHERE CONDITION GROUP BY column_name; SQLite HAVING Clause: SELECT SUM(column_name) FROM table_name WHERE CONDITION GROUP BY column_name HAVING (arithematic function condition); SQLite INSERT INTO Statement: INSERT INTO table_name( column1, column2....columnN) VALUES ( value1, value2....valueN); SQLite IN Clause: SELECT column1, column2....columnN FROM table_name WHERE column_name IN (val-1, val-2,...val-N); SQLite Like Clause: SELECT column1, column2....columnN FROM table_name WHERE column_name LIKE { PATTERN }; SQLite NOT IN Clause: SELECT column1, column2....columnN FROM table_name WHERE column_name NOT IN (val-1, val-2,...val-N); SQLite ORDER BY Clause: SELECT column1, column2....columnN FROM table_name WHERE CONDITION ORDER BY column_name {ASC|DESC}; SQLite PRAGMA Statement: PRAGMA pragma_name; For example: PRAGMA page_size; PRAGMA cache_size = 1024; PRAGMA table_info(table_name);
- 26. TUTORIALS POINT Simply Easy Learning SQLite RELEASE SAVEPOINT Statement: RELEASE savepoint_name; SQLite REINDEX Statement: REINDEX collation_name; REINDEX database_name.index_name; REINDEX database_name.table_name; SQLite ROLLBACK Statement: ROLLBACK; or ROLLBACK TO SAVEPOINT savepoint_name; SQLite SAVEPOINT Statement: SAVEPOINT savepoint_name; SQLite SELECT Statement: SELECT column1, column2....columnN FROM table_name; SQLite UPDATE Statement: UPDATE table_name SET column1 = value1, column2 = value2....columnN=valueN [ WHERE CONDITION ]; SQLite VACUUM Statement: VACUUM; SQLite WHERE Clause: SELECT column1, column2....columnN FROM table_name WHERE CONDITION;
- 27. TUTORIALS POINT Simply Easy Learning SQLite Data Type SQLite data type is an attribute that specifies type of data of any object. Each column, variable and expression has related data type in SQLite. You would use these data types while creating your tables. SQLite uses a more general dynamic type system. In SQLite, the datatype of a value is associated with the value itself, not with its container. SQLite Storage Classes: Each value stored in an SQLite database has one of the following storage classes: Storage Class Description NULL The value is a NULL value. INTEGER The value is a signed integer, stored in 1, 2, 3, 4, 6, or 8 bytes depending on the magnitude of the value. REAL The value is a floating point value, stored as an 8-byte IEEE floating point number. TEXT The value is a text string, stored using the database encoding (UTF-8, UTF-16BE or UTF-16LE) BLOB The value is a blob of data, stored exactly as it was input. SQLite storage class is slightly more general than a datatype. The INTEGER storage class, for example, includes 6 different integer datatypes of different lengths. SQLite Affinity Type: SQLite supports the concept of type affinity on columns. Any column can still store any type of data but the preferred storage class for a column is called its affinity. Each table column in an SQLite3 database is assigned one of the following type affinities: Affinity Description TEXT This column stores all data using storage classes NULL, TEXT or BLOB. NUMERIC This column may contain values using all five storage classes. INTEGER Behaves the same as a column with NUMERIC affinity with an exception in a CAST CHAPTER 5
- 28. TUTORIALS POINT Simply Easy Learning expression. REAL Behaves like a column with NUMERIC affinity except that it forces integer values into floating point representation NONE A column with affinity NONE does not prefer one storage class over another and no attempt is made to coerce data from one storage class into another. SQLite Affinity and Type Names: Following table lists down various data type names which can be used while creating SQLite3 tables and corresponding applied affinity also has been shown: Data Type Affinity INT INTEGER TINYINT SMALLINT MEDIUMINT BIGINT UNSIGNED BIG INT INT2 INT8 INTEGER CHARACTER(20) VARCHAR(255) VARYING CHARACTER(255) NCHAR(55) NATIVE CHARACTER(70) NVARCHAR(100) TEXT CLOB TEXT
- 29. TUTORIALS POINT Simply Easy Learning BLOB no datatype specified NONE REAL DOUBLE DOUBLE PRECISION FLOAT REAL NUMERIC DECIMAL(10,5) BOOLEAN DATE DATETIME NUMERIC Boolean Datatype: SQLite does not have a separate Boolean storage class. Instead, Boolean values are stored as integers 0 (false) and 1 (true). Date and Time Datatype: SQLite does not have a separate storage class for storing dates and/or times, but SQLite is capable of storing dates and times as TEXT, REAL or INTEGER values. Storage Class Date Formate TEXT A date in a format like "YYYY-MM-DD HH:MM:SS.SSS". REAL The number of days since noon in Greenwich on November 24, 4714 B.C. INTEGER The number of seconds since 1970-01-01 00:00:00 UTC. You can chose to store dates and times in any of these formats and freely convert between formats using the built-in date and time functions.
- 30. TUTORIALS POINT Simply Easy Learning SQLite Create Database The SQLite sqlite3 command is used to create new SQLite database. You do not need to have any special privilege to create a database. Syntax: Basic syntax of sqlite3 command is as follows: $sqlite3 DatabaseName.db Always, database name should be unique within the RDBMS. Example: If you want to create new database <testDB.db>, then SQLite3 statement would be as follows: $sqlite3 testDB.db SQLite version 3.7.15.2 2013-01-09 11:53:05 Enter ".help" for instructions Enter SQL statements terminated with a ";" sqlite> Above command will create a file testDB.db in the current directory. This file will be used as database by SQLite engine. If you have noticed while creating database, sqlite3 command will provide a sqlite>prompt after creating database file successfully. Once a database is created, you can check it in the list of databases using SQLite .databases command as follows: sqlite>.databases seq name file --- --------------- ---------------------- 0 main /home/sqlite/testDB.db You will use SQLite .quit command to come out of the sqlite prompt as follows: sqlite>.quit $ CHAPTER 6
- 31. TUTORIALS POINT Simply Easy Learning The .dump Command You can use .dump dot command to export complete database in a text file using SQLite command at command prompt as follows: $sqlite3 testDB.db .dump > testDB.sql Above command will convert the entire contents of testDB.db database into SQLite statements and dump it into ASCII text file testDB.sql. You can do restoration from the generated testDB.sql in simple way as follows: $sqlite3 testDB.db < testDB.sql At this moment your database is empty, so you can try above two procedures once you have few tables and data in your database. For now, let's proceed to next chapter.
- 32. TUTORIALS POINT Simply Easy Learning SQLite Attach Database Consider a case when you have multiple databases available and you want to use any one of them at a time. SQLite ATTACH DTABASE statement is used to select a particular database, and after this command, all SQLite statements will be executed under the attached database. Syntax: Basic syntax of SQLite ATTACH DATABASE statement is as follows: ATTACH DATABASE 'DatabaseName' As 'Alias-Name'; Above command will also create a database in case database is already not created, otherwise it will just attach database file name with logical database 'Alias-Name'. Example: If you want to attach an existing database testDB.db, then ATTACH DATABASE statement would be as follows: sqlite> ATTACH DATABASE 'testDB.db' as 'TEST'; Use SQLite .database command to display attached database. sqlite> .database seq name file --- --------------- ---------------------- 0 main /home/sqlite/testDB.db 2 test /home/sqlite/testDB.db The database names main and temp are reserved for the primary database and database to hold temporary tables and other temporary data objects. Both of these database names exist for every database connection and should not be used for attachment, otherwise you will get a warning message something as follows: sqlite> ATTACH DATABASE 'testDB.db' as 'TEMP'; Error: database TEMP is already in use sqlite> ATTACH DATABASE 'testDB.db' as 'main'; Error: database TEMP is already in use CHAPTER 7
- 33. TUTORIALS POINT Simply Easy Learning SQLite Detach Database SQLite DETACH DTABASE statement is used to detach and dissociate a named database from a database connection which was previously attached using ATTACH statement. If the same database file has been attached with multiple aliases, then DETACH command will disconnect only given name and rest of the attachement will still continue. You cannot detach the main or temp databases. If the database is an in-memory or temporary database, the database will be destroyed and the contents will be lost. Syntax: Basic syntax of SQLite DETACH DATABASE 'Alias-Name' statement is as follows: DETACH DATABASE 'Alias-Name'; Here 'Alias-Name' is the same alias, which you had used while attaching database using ATTACH statement. Example: Consider you have a database, which you created in previous chapter and attached it with 'test' and 'currentDB' as we can see using .database command: sqlite>.databases seq name file --- --------------- ---------------------- 0 main /home/sqlite/testDB.db 2 test /home/sqlite/testDB.db 3 currentDB /home/sqlite/testDB.db Now let's try to detach 'currentDB' from testDB.db as follows: sqlite> DETACH DATABASE 'currentDB'; Now, if you will check current attachment, you will find that testDB.db is still connected with 'test' and 'main'. sqlite>.databases seq name file --- --------------- ---------------------- 0 main /home/sqlite/testDB.db 2 test /home/sqlite/testDB.db CHAPTER 8
- 34. TUTORIALS POINT Simply Easy Learning SQLite Create Table The SQLite CREATE TABLE statement is used to create a new table in any of the given database. Creating a basic table involves naming the table and defining its columns and each column's data type. Syntax: Basic syntax of CREATE TABLE statement is as follows: CREATE TABLE database_name.table_name( column1 datatype PRIMARY KEY(one or more columns), column2 datatype, column3 datatype, ..... columnN datatype, ); CREATE TABLE is the keyword telling the database system to create a new table. The unique name or identifier for the table follows the CREATE TABLE statement. Optionally you can specify database_name along with table_name. Example: Following is an example, which creates a COMPANY table with ID as primary key and NOT NULL are the constraints showing that these fields can not be NULL while creating records in this table: sqlite> CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL ); Let us create one more table, which we will use in our exercises in subsequent chapters: sqlite> CREATE TABLE DEPARTMENT( ID INT PRIMARY KEY NOT NULL, DEPT CHAR(50) NOT NULL, EMP_ID INT NOT NULL ); CHAPTER 9
- 35. TUTORIALS POINT Simply Easy Learning You can verify if your table has been created successfully using SQLIte command .tables command, which will be used to list down all the tables in an attached database. sqlite>.tables COMPANY DEPARTMENT Here, you can see COMPANY table twice because it's showing COMPANY table for main database and test.COMPANY table for 'test' alias created for your testDB.db. You can get complete information about a table using SQLite .schema command as follows: sqlite>.schema COMPANY CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL );
- 36. TUTORIALS POINT Simply Easy Learning SQLite Drop Table The SQLite DROP TABLE statement is used to remove a table definition and all associated data, indexes, triggers, constraints and permission specifications for that table. You have to be careful while using this command because once a table is deleted then all the information available in the table would also be lost forever. Syntax: Basic syntax of DROP TABLE statement is as follows. You can optionally specify database name along with table name as follows: DROP TABLE database_name.table_name; Example: Let us first verify COMPANY table and then we would delete it from the database. sqlite>.tables COMPANY test.COMPANY This means COMPANY table is available in the database, so let us drop it as follows: sqlite>DROP TABLE COMPANY; sqlite> Now, if you would try .TABLES command, then you will not find COMPANY table anymore: sqlite>.tables sqlite> It shows nothing means the table from your database has been dropped successfully. CHAPTER 10
- 37. TUTORIALS POINT Simply Easy Learning SQLite Insert Query The SQLite INSERT INTO Statement is used to add new rows of data into a table in the database. Syntax: There are two basic syntaxes of INSERT INTO statement as follows: INSERT INTO TABLE_NAME (column1, column2, column3,...columnN)] VALUES (value1, value2, value3,...valueN); Here, column1, column2,...columnN are the names of the columns in the table into which you want to insert data. You may not need to specify the column(s) name in the SQLite query if you are adding values for all the columns of the table. But make sure the order of the values is in the same order as the columns in the table. The SQLite INSERT INTO syntax would be as follows: INSERT INTO TABLE_NAME VALUES (value1,value2,value3,...valueN); Example: Consider you already have created COMPANY table in your testDB.db as follows: sqlite> CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL ); Now, following statements would create six records in COMPANY table: INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (1, 'Paul', 32, 'California', 20000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (2, 'Allen', 25, 'Texas', 15000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (3, 'Teddy', 23, 'Norway', 20000.00 ); CHAPTER 11
- 38. TUTORIALS POINT Simply Easy Learning INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (5, 'David', 27, 'Texas', 85000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (6, 'Kim', 22, 'South-Hall', 45000.00 ); You can create a record in COMPANY table using second syntax as follows: INSERT INTO COMPANY VALUES (7, 'James', 24, 'Houston', 10000.00 ); All the above statements would create following records in COMPANY table. Next chapter will teach you how to display all these records from a table. ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Populate one table using another table: You can populate data into a table through select statement over another table provided another table has a set of fields, which are required to populate first table. Here is the syntax: INSERT INTO first_table_name [(column1, column2, ... columnN)] SELECT column1, column2, ...columnN FROM second_table_name [WHERE condition]; For now, you can skip above statement, first let's learn SELECT and WHERE clauses, which will be covered in subsequent chapters.
- 39. TUTORIALS POINT Simply Easy Learning SQLite Select Query SQLite SELECT statement is used to fetch the data from a SQLite database table which returns data in the form of result table. These result tables are also called result-sets. Syntax: The basic syntax of SQLite SELECT statement is as follows: SELECT column1, column2, columnN FROM table_name; Here, column1, column2...are the fields of a table, whose values you want to fetch. If you want to fetch all the fields available in the field, then you can use the following syntax: SELECT * FROM table_name; Example: Consider COMPANY table is having following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following is an example to fetch and display all these records using SELECT statement. Here, first three commands have been used to set properly formatted output. sqlite>.header on sqlite>.mode column sqlite> SELECT * FROM COMPANY; Finally, you will get the following result: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- CHAPTER 12
- 40. TUTORIALS POINT Simply Easy Learning 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 If you want to fetch only selected fields of COMPANY table, then use the following query: sqlite> SELECT ID, NAME, SALARY FROM COMPANY; Above query will produce the following result: ID NAME SALARY ---------- ---------- ---------- 1 Paul 20000.0 2 Allen 15000.0 3 Teddy 20000.0 4 Mark 65000.0 5 David 85000.0 6 Kim 45000.0 7 James 10000.0 Setting output column width: Sometimes, you will face a problem related to truncated output in case of .mode column which happens because of default width of the column to be displayed. What you can do is that you can set column displayable column width using .width num, num.... command as follows: sqlite>.width 10, 20, 10 sqlite>SELECT * FROM COMPANY; Above .width command sets first column width to 10, second column width to 20 and third column width to 10. So finally above SELECT statement will give the following result: ID NAME AGE ADDRESS SALARY ---------- -------------------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Schema Information: Because all the dot commads are available at SQLite prompt only, so while doing your programming with SQLite, you will use the following statement to list down all the tables created in your database using the following SELECT statement with sqlite_master table: sqlite> SELECT tbl_name FROM sqlite_master WHERE type = 'table'; Assuming you have only COMPANY table in your testDB.db, this will produce the following result: tbl_name ----------
- 41. TUTORIALS POINT Simply Easy Learning COMPANY You can list down complete information about COMPANY table as follows: sqlite> SELECT sql FROM sqlite_master WHERE type = 'table' AND tbl_name = 'COMPANY'; Assuming you have only COMPANY table in your testDB.db, this will produce the following result: CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL )
- 42. TUTORIALS POINT Simply Easy Learning SQLite Operators What is an operator in SQLite? An operator is a reserved word or a character used primarily in an SQLite statement's WHERE clause to perform operation(s), such as comparisons and arithmetic operations. Operators are used to specify conditions in an SQLite statement and to serve as conjunctions for multiple conditions in a statement. Arithmetic operators Comparison operators Logical operators Bitwise operators SQLite Arithmetic Operators: Assume variable a holds 10 and variable b holds 20, then: Operator Description Example + Addition - Adds values on either side of the operator a + b will give 30 - Subtraction - Subtracts right hand operand from left hand operand a - b will give -10 * Multiplication - Multiplies values on either side of the operator a * b will give 200 / Division - Divides left hand operand by right hand operand b / a will give 2 % Modulus - Divides left hand operand by right hand operand and returns remainder b % a will give 0 CHAPTER 13
- 43. TUTORIALS POINT Simply Easy Learning Example Here are simple examples showing usage of SQLite Arithmetic Operators: sqlite> .mode line sqlite> select 10 + 20; 10 + 20 = 30 sqlite> select 10 - 20; 10 - 20 = -10 sqlite> select 10 * 20; 10 * 20 = 200 sqlite> select 10 / 5; 10 / 5 = 2 sqlite> select 12 % 5; 12 % 5 = 2 SQLite Comparison Operators: Assume variable a holds 10 and variable b holds 20, then: Operator Description Example == Checks if the values of two operands are equal or not, if yes then condition becomes true. (a == b) is not true. = Checks if the values of two operands are equal or not, if yes then condition becomes true. (a = b) is not true. != Checks if the values of two operands are equal or not, if values are not equal then condition becomes true. (a != b) is true. <> Checks if the values of two operands are equal or not, if values are not equal then condition becomes true. (a <> b) is true. > Checks if the value of left operand is greater than the value of right operand, if yes then condition becomes true. (a > b) is not true. < Checks if the value of left operand is less than the value of right operand, if yes then condition becomes true. (a < b) is true. >= Checks if the value of left operand is greater than or equal to the value of right operand, if yes then condition becomes true. (a >= b) is not true. <= Checks if the value of left operand is less than or equal to the value of right operand, if yes then condition becomes true. (a <= b) is true. !< Checks if the value of left operand is not less than the value of right operand, if yes then condition becomes true. (a !< b) is false. !> Checks if the value of left operand is not greater than the value of right operand, if yes (a !> b)
- 44. TUTORIALS POINT Simply Easy Learning then condition becomes true. is true. Example Consider COMPANY table has the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Below example will show the usage of various SQLite Comparison Operators. Here, we have used WHERE clause, which will be explained in a separate chapter but for now you can understand that WHERE clause is used to put a conditional statement along with SELECT statement. Following SELECT statement lists down all the records having SALARY greater than 50,000.00: sqlite> SELECT * FROM COMPANY WHERE SALARY > 50000; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 Following SELECT statement lists down all the records having SALARY equal to 20,000.00: sqlite> SELECT * FROM COMPANY WHERE SALARY = 20000; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 3 Teddy 23 Norway 20000.0 Following SELECT statement lists down all the records having SALARY not equal to 20,000.00: sqlite> SELECT * FROM COMPANY WHERE SALARY != 20000; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 2 Allen 25 Texas 15000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following SELECT statement lists down all the records having SALARY not equal to 20,000.00: sqlite> SELECT * FROM COMPANY WHERE SALARY <> 20000; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 2 Allen 25 Texas 15000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0
- 45. TUTORIALS POINT Simply Easy Learning 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following SELECT statement lists down all the records having SALARY greater than or equal to 65,000.00: sqlite> SELECT * FROM COMPANY WHERE SALARY >= 65000; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 SQLite Logical Operators: Here is a list of all the logical operators available in SQLite. Operator Description AND The AND operator allows the existence of multiple conditions in an SQL statement's WHERE clause. BETWEEN The BETWEEN operator is used to search for values that are within a set of values, given the minimum value and the maximum value. EXISTS The EXISTS operator is used to search for the presence of a row in a specified table that meets certain criteria. IN The IN operator is used to compare a value to a list of literal values that have been specified. NOT IN The negation of IN operator which is used to compare a value to a list of literal values that have been specified. LIKE The LIKE operator is used to compare a value to similar values using wildcard operators. GLOB The GLOB operator is used to compare a value to similar values using wildcard operators. Also, GLOB is case sensitive, unlike LIKE. NOT The NOT operator reverses the meaning of the logical operator with which it is used. Eg. NOT EXISTS, NOT BETWEEN, NOT IN, etc. This is negate operator. OR The OR operator is used to combine multiple conditions in an SQL statement's WHERE clause. IS NULL The NULL operator is used to compare a value with a NULL value. IS The IS operator work like = IS NOT The IS operator work like != || Adds two different strings and make new one. UNIQUE The UNIQUE operator searches every row of a specified table for uniqueness (no duplicates). Example Consider COMPANY table has the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0
- 46. TUTORIALS POINT Simply Easy Learning 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Here are simple examples showing usage of SQLite Logical Operators. Following SELECT statement lists down all the records where AGE is greater than or equal to 25 and salary is greater than or equal to 65000.00: sqlite> SELECT * FROM COMPANY WHERE AGE >= 25 AND SALARY >= 65000; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 Following SELECT statement lists down all the records where AGE is greater than or equal to 25 OR salary is greater than or equal to 65000.00: sqlite> SELECT * FROM COMPANY WHERE AGE >= 25 OR SALARY >= 65000; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 Following SELECT statement lists down all the records where AGE is not NULL which means all the records because none of the record is having AGE equal to NULL: sqlite> SELECT * FROM COMPANY WHERE AGE IS NOT NULL; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following SELECT statement lists down all the records where NAME starts with 'Ki', does not matter what comes after 'Ki'. sqlite> SELECT * FROM COMPANY WHERE NAME LIKE 'Ki%'; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 6 Kim 22 South-Hall 45000.0 Following SELECT statement lists down all the records where NAME starts with 'Ki', does not matter what comes after 'Ki': sqlite> SELECT * FROM COMPANY WHERE NAME GLOB 'Ki*'; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 6 Kim 22 South-Hall 45000.0 Following SELECT statement lists down all the records where AGE value is either 25 or 27: sqlite> SELECT * FROM COMPANY WHERE AGE IN ( 25, 27 ); ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ----------
- 47. TUTORIALS POINT Simply Easy Learning 2 Allen 25 Texas 15000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 Following SELECT statement lists down all the records where AGE value is neither 25 nor 27: sqlite> SELECT * FROM COMPANY WHERE AGE NOT IN ( 25, 27 ); ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 3 Teddy 23 Norway 20000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following SELECT statement lists down all the records where AGE value is in BETWEEN 25 AND 27: sqlite> SELECT * FROM COMPANY WHERE AGE BETWEEN 25 AND 27; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 2 Allen 25 Texas 15000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 Following SELECT statement makes use of SQL sub-query where sub-query finds all the records with AGE field having SALARY > 65000 and later WHERE clause is being used along with EXISTS operator to list down all the records where AGE from the outside query exists in the result returned by sub-query: sqlite> SELECT AGE FROM COMPANY WHERE EXISTS (SELECT AGE FROM COMPANY WHERE SALARY > 65000); AGE ---------- 32 25 23 25 27 22 24 Following SELECT statement makes use of SQL sub-query where subquery finds all the records with AGE field having SALARY > 65000 and later WHERE clause is being used along with > operator to list down all the records where AGE from outside query is greater than the age in the result returned by sub-query: sqlite> SELECT * FROM COMPANY WHERE AGE > (SELECT AGE FROM COMPANY WHERE SALARY > 65000); ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 SQLite Bitwise Operators: Bitwise operator works on bits and perform bit-by-bit operation. The truth table for & and | is as follows: P Q p & q p | q 0 0 0 0 0 1 0 1
- 48. TUTORIALS POINT Simply Easy Learning 1 1 1 1 1 0 0 1 Assume if A = 60; and B = 13; now in binary format, they will be as follows: A = 0011 1100 B = 0000 1101 ----------------- A&B = 0000 1100 A|B = 0011 1101 ~A = 1100 0011 The Bitwise operators supported by SQLite language are listed in the following table. Assume variable A holds 60 and variable B holds 13, then: Operator Description Example & Binary AND Operator copies a bit to the result if it exists in both operands. (A & B) will give 12 which is 0000 1100 | Binary OR Operator copies a bit if it exists in either operand. (A | B) will give 61 which is 0011 1101 ~ Binary Ones Complement Operator is unary and has the effect of 'flipping' bits. (~A ) will give -60 which is 1100 0011 << Binary Left Shift Operator. The left operands value is moved left by the number of bits specified by the right operand. A << 2 will give 240 which is 1111 0000 >> Binary Right Shift Operator. The left operands value is moved right by the number of bits specified by the right operand. A >> 2 will give 15 which is 0000 1111 Example Here are simple examples showing usage of SQLite Bitwise Operators: sqlite> .mode line sqlite> select 60 | 13; 60 | 13 = 61 sqlite> select 60 & 13; 60 & 13 = 12 sqlite> select 60 ^ 13; 10 * 20 = 200 sqlite> select (~60); (~60) = -61 sqlite> select (60 << 2);
- 49. TUTORIALS POINT Simply Easy Learning (60 << 2) = 240 sqlite> select (60 >> 2); (60 >> 2) = 15
- 50. TUTORIALS POINT Simply Easy Learning SQLite Expressions An expression is a combination of one or more values, operators and SQL functions that evaluate to a value. SQL EXPRESSIONs are like formulas and they are written in query language. You can also use to query the database for specific set of data. Syntax: Consider the basic syntax of the SELECT statement as follows: SELECT column1, column2, columnN FROM table_name WHERE [CONTION | EXPRESSION]; There are different types of SQLite expressions, which are mentioned below: SQLite - Boolean Expressions: SQLite Boolean Expressions fetch the data on the basis of matching single value. Following is the syntax: SELECT column1, column2, columnN FROM table_name WHERE SINGLE VALUE MATCHTING EXPRESSION; Consider COMPANY table has the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Here is simple examples showing usage of SQLite Boolean Expressions: sqlite> SELECT * FROM COMPANY WHERE SALARY = 10000; CHAPTER 14
- 51. TUTORIALS POINT Simply Easy Learning ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 4 James 24 Houston 10000.0 SQLite - Numeric Expression: These expressions are used to perform any mathematical operation in any query. Following is the syntax: SELECT numerical_expression as OPERATION_NAME [FROM table_name WHERE CONDITION] ; Here, numerical_expression is used for mathematical expression or any formula. Following is a simple example showing usage of SQLite Numeric Expressions: sqlite> SELECT (15 + 6) AS ADDITION ADDITION = 21 There are several built-in functions like avg(), sum(), count(), etc., to perform what is known as aggregate data calculations against a table or a specific table column. sqlite> SELECT COUNT(*) AS "RECORDS" FROM COMPANY; RECORDS = 7 SQLite - Date Expressions: Date Expressions return current system date and time values and these expressions will be used in various data manipulations. sqlite> SELECT CURRENT_TIMESTAMP; CURRENT_TIMESTAMP = 2013-03-17 10:43:35
- 52. TUTORIALS POINT Simply Easy Learning SQLite Where Clause The SQLite WHERE clause is used to specify a condition while fetching the data from one table or multiple tables. If the given condition is satisfied, means true, then it returns specific value from the table. You would use WHERE clause to filter the records and fetching only necessary records. The WHERE clause not only used in SELECT statement, but it is also used in UPDATE, DELETE statement, etc., which we would study in subsequent chapters. Syntax: The basic syntax of SQLite SELECT statement with WHERE clause is as follows: SELECT column1, column2, columnN FROM table_name WHERE [condition] Example: You can specify a condition using Comparision or Logical Operators like >, <, =, LIKE, NOT, etc. Consider COMPANY table has the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Here are simple examples showing usage of SQLite Logical Operators. Following SELECT statement lists down all the records where AGE is greater than or equal to 25 AND salary is greater than or equal to 65000.00: sqlite> SELECT * FROM COMPANY WHERE AGE >= 25 AND SALARY >= 65000; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 4 Mark 25 Rich-Mond 65000.0 CHAPTER 15
- 53. TUTORIALS POINT Simply Easy Learning 5 David 27 Texas 85000.0 Following SELECT statement lists down all the records where AGE is greater than or equal to 25 OR salary is greater than or equal to 65000.00: sqlite> SELECT * FROM COMPANY WHERE AGE >= 25 OR SALARY >= 65000; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 Following SELECT statement lists down all the records where AGE is not NULL which means all the records because none of the record is having AGE equal to NULL: sqlite> SELECT * FROM COMPANY WHERE AGE IS NOT NULL; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following SELECT statement lists down all the records where NAME starts with 'Ki', does not matter what comes after 'Ki'. sqlite> SELECT * FROM COMPANY WHERE NAME LIKE 'Ki%'; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 6 Kim 22 South-Hall 45000.0 Following SELECT statement lists down all the records where NAME starts with 'Ki', does not matter what comes after 'Ki': sqlite> SELECT * FROM COMPANY WHERE NAME GLOB 'Ki*'; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 6 Kim 22 South-Hall 45000.0 Following SELECT statement lists down all the records where AGE value is either 25 or 27: sqlite> SELECT * FROM COMPANY WHERE AGE IN ( 25, 27 ); ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 2 Allen 25 Texas 15000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 Following SELECT statement lists down all the records where AGE value is neither 25 nor 27: sqlite> SELECT * FROM COMPANY WHERE AGE NOT IN ( 25, 27 ); ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 3 Teddy 23 Norway 20000.0 6 Kim 22 South-Hall 45000.0
- 54. TUTORIALS POINT Simply Easy Learning 7 James 24 Houston 10000.0 Following SELECT statement lists down all the records where AGE value is in BETWEEN 25 AND 27: sqlite> SELECT * FROM COMPANY WHERE AGE BETWEEN 25 AND 27; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 2 Allen 25 Texas 15000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 Following SELECT statement makes use of SQL sub-query where sub-query finds all the records with AGE field having SALARY > 65000 and later WHERE clause is being used along with EXISTS operator to list down all the records where AGE from the outside query exists in the result returned by sub-query: sqlite> SELECT AGE FROM COMPANY WHERE EXISTS (SELECT AGE FROM COMPANY WHERE SALARY > 65000); AGE ---------- 32 25 23 25 27 22 24 Following SELECT statement makes use of SQL sub-query where sub-query finds all the records with AGE field having SALARY > 65000 and later WHERE clause is being used along with > operator to list down all the records where AGE from outside query is greater than the age in the result returned by sub-query: sqlite> SELECT * FROM COMPANY WHERE AGE > (SELECT AGE FROM COMPANY WHERE SALARY > 65000); ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0
- 55. TUTORIALS POINT Simply Easy Learning SQLite AND and OR Operator The SQLite AND and OR operators are used to combine multiple conditions to narrow down selected data in an SQLite statement. These two operators are called conjunctive operators. These operators provide a means to make multiple comparisons with different operators in the same SQLite statement. The AND Operator: The AND operator allows the existence of multiple conditions in an SQLite statement's WHERE clause. While using AND operator, complete condition will be assumed true when all the conditions are true. For example, [condition1] AND [condition2] will be true only when both condition1 and condition2 are true. Syntax: The basic syntax of AND operator with WHERE clause is as follows: SELECT column1, column2, columnN FROM table_name WHERE [condition1] AND [condition2]...AND [conditionN]; You can combine N number of conditions using AND operator. For an action to be taken by the SQLite statement, whether it be a transaction or query, all conditions separated by the AND must be TRUE. Example: Consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following SELECT statement lists down all the records where AGE is greater than or equal to 25 ANDsalary is greater than or equal to 65000.00: sqlite> SELECT * FROM COMPANY WHERE AGE >= 25 AND SALARY >= 65000; CHAPTER 16
- 56. TUTORIALS POINT Simply Easy Learning ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 The OR Operator: The OR operator is also used to combine multiple conditions in an SQLite statement's WHERE clause. While using OR operator, complete condition will be assumed true when at least any of the conditions is true. For example, [condition1] OR [condition2] will be true if either condition1 or condition2 is true. Syntax: The basic syntax of OR operator with WHERE clause is as follows: SELECT column1, column2, columnN FROM table_name WHERE [condition1] OR [condition2]...OR [conditionN] You can combine N number of conditions using OR operator. For an action to be taken by the SQLite statement, whether it be a transaction or query, only any ONE of the conditions separated by the OR must be TRUE. Example: Consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following SELECT statement lists down all the records where AGE is greater than or equal to 25 ORsalary is greater than or equal to 65000.00: sqlite> SELECT * FROM COMPANY WHERE AGE >= 25 OR SALARY >= 65000; ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0
- 57. TUTORIALS POINT Simply Easy Learning SQLite Update Query The SQLite UPDATE Query is used to modify the existing records in a table. You can use WHERE clause with UPDATE query to update selected rows, otherwise all the rows would be updated. Syntax: The basic syntax of UPDATE query with WHERE clause is as follows: UPDATE table_name SET column1 = value1, column2 = value2...., columnN = valueN WHERE [condition]; You can combine N number of conditions using AND or OR operators. Example: Consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following is an example, which would update ADDRESS for a customer whose ID is 6: sqlite> UPDATE COMPANY SET ADDRESS = 'Texas' WHERE ID = 6; Now, COMPANY table would have the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 CHAPTER 17
- 58. TUTORIALS POINT Simply Easy Learning 6 Kim 22 Texas 45000.0 7 James 24 Houston 10000.0 If you want to modify all ADDRESS and SALARY column values in COMPANY table, you do not need to use WHERE clause and UPDATE query would be as follows: sqlite> UPDATE COMPANY SET ADDRESS = 'Texas', SALARY = 20000.00; Now, COMPANY table will have the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 Texas 20000.0 2 Allen 25 Texas 20000.0 3 Teddy 23 Texas 20000.0 4 Mark 25 Texas 20000.0 5 David 27 Texas 20000.0 6 Kim 22 Texas 20000.0 7 James 24 Texas 20000.0
- 59. TUTORIALS POINT Simply Easy Learning SQLite Delete Query The SQLite DELETE Query is used to delete the existing records from a table. You can use WHERE clause with DELETE query to delete selected rows, otherwise all the records would be deleted. Syntax: The basic syntax of DELETE query with WHERE clause is as follows: DELETE FROM table_name WHERE [condition]; You can combine N number of conditions using AND or OR operators. Example: Consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following is an example, which would DELETE a customer whose ID is 7: sqlite> DELETE FROM COMPANY WHERE ID = 7; Now, COMPANY table will have the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 CHAPTER 18
- 60. TUTORIALS POINT Simply Easy Learning 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 If you want to DELETE all the records from COMPANY table, you do not need to use WHERE clause with DELETE query, which would be as follows: sqlite> DELETE FROM COMPANY; Now, COMPANY table does not have any record because all the records have been deleted by DELETE statement.
- 61. TUTORIALS POINT Simply Easy Learning SQLite Like Clause The SQLite LIKE operator is used to match text values against a pattern using wildcards. If the search expression can be matched to the pattern expression, the LIKE operator will return true, which is 1. There are two wildcards used in conjunction with the LIKE operator: The percent sign (%) The underscore (_) The percent sign represents zero, one, or multiple numbers or characters. The underscore represents a single number or character. These symbols can be used in combinations. Syntax: The basic syntax of % and _ is as follows: SELECT FROM table_name WHERE column LIKE 'XXXX%' or SELECT FROM table_name WHERE column LIKE '%XXXX%' or SELECT FROM table_name WHERE column LIKE 'XXXX_' or SELECT FROM table_name WHERE column LIKE '_XXXX' or SELECT FROM table_name WHERE column LIKE '_XXXX_' You can combine N number of conditions using AND or OR operators. Here XXXX could be any numeric or string value. CHAPTER 19
- 62. TUTORIALS POINT Simply Easy Learning Example: Here are number of examples showing WHERE part having different LIKE clause with '%' and '_' operators: Statement Description WHERE SALARY LIKE '200%' Finds any values that start with 200 WHERE SALARY LIKE '%200%' Finds any values that have 200 in any position WHERE SALARY LIKE '_00%' Finds any values that have 00 in the second and third positions WHERE SALARY LIKE '2_%_%' Finds any values that start with 2 and are at least 3 characters in length WHERE SALARY LIKE '%2' Finds any values that end with 2 WHERE SALARY LIKE '_2%3' Finds any values that have a 2 in the second position and end with a 3 WHERE SALARY LIKE '2___3' Finds any values in a five-digit number that start with 2 and end with 3 Let us take a real example, consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following is an example, which would display all the records from COMPANY table where AGE starts with 2: sqlite> SELECT * FROM COMPANY WHERE AGE LIKE '2%'; This would produce the following result: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following is an example, which would display all the records from COMPANY table where ADDRESS will have a hyphen (-) inside the text: sqlite> SELECT * FROM COMPANY WHERE ADDRESS LIKE '%-%'; This would produce the following result: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 4 Mark 25 Rich-Mond 65000.0 6 Kim 22 South-Hall 45000.0
- 63. TUTORIALS POINT Simply Easy Learning
- 64. TUTORIALS POINT Simply Easy Learning SQLite Glob Clause The SQLite GLOB operator is used to match only text values against a pattern using wildcards. If the search expression can be matched to the pattern expression, the GLOB operator will return true, which is 1. Unlike LIKE operator, GLOB is case sensitive and it follows syntax of UNIX for specifying the following wildcards. The asterisk sign (*) The question mark (?) The asterisk sign represents zero or multiple numbers or characters. The ? represents a single number or character. Syntax: The basic syntax of * and ? is as follows: SELECT FROM table_name WHERE column GLOB 'XXXX*' or SELECT FROM table_name WHERE column GLOB '*XXXX*' or SELECT FROM table_name WHERE column GLOB 'XXXX?' or SELECT FROM table_name WHERE column GLOB '?XXXX' or SELECT FROM table_name WHERE column GLOB '?XXXX?' or CHAPTER 20
- 65. TUTORIALS POINT Simply Easy Learning SELECT FROM table_name WHERE column GLOB '????' You can combine N number of conditions using AND or OR operators. Here XXXX could be any numberic or string value. Example: Here are number of examples showing WHERE part having different LIKE clause with '*' and '?' operators: Statement Description WHERE SALARY GLOB '200*' Finds any values that start with 200 WHERE SALARY GLOB '*200*' Finds any values that have 200 in any position WHERE SALARY GLOB '?00*' Finds any values that have 00 in the second and third positions WHERE SALARY GLOB '2??' Finds any values that start with 2 and are at least 3 characters in length WHERE SALARY GLOB '*2' Finds any values that end with 2 WHERE SALARY GLOB '?2*3' Finds any values that have a 2 in the second position and end with a 3 WHERE SALARY GLOB '2???3' Finds any values in a five-digit number that start with 2 and end with 3 Let us take a real example, consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following is an example, which would display all the records from COMPANY table where AGE starts with 2: sqlite> SELECT * FROM COMPANY WHERE AGE GLOB '2*'; This would produce following result: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following is an example, which would display all the records from COMPANY table where ADDRESS will have a hyphen (-) inside the text: sqlite> SELECT * FROM COMPANY WHERE ADDRESS GLOB '*-*'; This would produce the following result:
- 66. TUTORIALS POINT Simply Easy Learning ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 4 Mark 25 Rich-Mond 65000.0 6 Kim 22 South-Hall 45000.0
- 67. TUTORIALS POINT Simply Easy Learning SQLite LIMIT Clause The SQLite LIMIT clause is used to limit the data amount returned by the SELECT statement. Syntax: The basic syntax of SELECT statement with LIMIT clause is as follows: SELECT column1, column2, columnN FROM table_name LIMIT [no of rows] Following is the syntax of LIMIT clause when it is used along with OFFSET clause: SELECT column1, column2, columnN FROM table_name LIMIT [no of rows] OFFSET [row num] SQLite engine will return rows starting from the next row to the given OFFSET as shown below in the last example. Example: Consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following is an example, which limits the row in the table according to the number of rows you want to fetch from table: sqlite> SELECT * FROM COMPANY LIMIT 6; This would produce the following result: CHAPTER 21
- 68. TUTORIALS POINT Simply Easy Learning ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 But in certain situations, you may need to pick up a set of records from a particular offset. Here is an example, which picks up 3 records starting from 3rd position: sqlite> SELECT * FROM COMPANY LIMIT 3 OFFSET 2; This would produce the following result: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0
- 69. TUTORIALS POINT Simply Easy Learning SQLite Order By Clause The SQLite ORDER BY clause is used to sort the data in ascending or descending order, based on one or more columns. Syntax: The basic syntax of ORDER BY clause is as follows: SELECT column-list FROM table_name [WHERE condition] [ORDER BY column1, column2, .. columnN] [ASC | DESC]; You can use more than one column in the ORDER BY clause. Make sure whatever column you are using to sort, that column should be available in column-list. Example: Consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following is an example, which would sort the result in descending order by SALARY: sqlite> SELECT * FROM COMPANY ORDER BY SALARY ASC; This would produce the following result: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 7 James 24 Houston 10000.0 2 Allen 25 Texas 15000.0 1 Paul 32 California 20000.0 CHAPTER 22
- 70. TUTORIALS POINT Simply Easy Learning 3 Teddy 23 Norway 20000.0 6 Kim 22 South-Hall 45000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 Following is an example, which would sort the result in descending order by NAME and SALARY: sqlite> SELECT * FROM COMPANY ORDER BY NAME, SALARY ASC; This would produce following result: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 2 Allen 25 Texas 15000.0 5 David 27 Texas 85000.0 7 James 24 Houston 10000.0 6 Kim 22 South-Hall 45000.0 4 Mark 25 Rich-Mond 65000.0 1 Paul 32 California 20000.0 3 Teddy 23 Norway 20000.0 Following is an example, which would sort the result in descending order by NAME: sqlite> SELECT * FROM COMPANY ORDER BY NAME DESC; This would produce the following result: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 3 Teddy 23 Norway 20000.0 1 Paul 32 California 20000.0 4 Mark 25 Rich-Mond 65000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 5 David 27 Texas 85000.0 2 Allen 25 Texas 15000.0
- 71. TUTORIALS POINT Simply Easy Learning SQLite Group By Clause The SQLite GROUP BY clause is used in collaboration with the SELECT statement to arrange identical data into groups. The GROUP BY clause follows the WHERE clause in a SELECT statement and precedes the ORDER BY clause. Syntax: The basic syntax of GROUP BY clause is given below. The GROUP BY clause must follow the conditions in the WHERE clause and must precede the ORDER BY clause if one is used. SELECT column-list FROM table_name WHERE [ conditions ] GROUP BY column1, column2....columnN ORDER BY column1, column2....columnN You can use more than one column in the GROUP BY clause. Make sure whatever column you are using to group, that column should be available in column-list. Example: Consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 If you want to know the total amount of salary on each customer, then GROUP BY query would be as follows: sqlite> SELECT NAME, SUM(SALARY) FROM COMPANY GROUP BY NAME; This would produce following result: CHAPTER 23
- 72. TUTORIALS POINT Simply Easy Learning NAME SUM(SALARY) ---------- ----------- Allen 15000.0 David 85000.0 James 10000.0 Kim 45000.0 Mark 65000.0 Paul 20000.0 Teddy 20000.0 Now, let us create three more records in COMPANY table using the following INSERT statements: INSERT INTO COMPANY VALUES (8, 'Paul', 24, 'Houston', 20000.00 ); INSERT INTO COMPANY VALUES (9, 'James', 44, 'Norway', 5000.00 ); INSERT INTO COMPANY VALUES (10, 'James', 45, 'Texas', 5000.00 ); Now, our table has the following records with duplicate names: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 8 Paul 24 Houston 20000.0 9 James 44 Norway 5000.0 10 James 45 Texas 5000.0 Again, let us use the same statement to group-by all the records using NAME column as follows: sqlite> SELECT NAME, SUM(SALARY) FROM COMPANY GROUP BY NAME ORDER BY NAME; This would produce the following result: NAME SUM(SALARY) ---------- ----------- Allen 15000 David 85000 James 20000 Kim 45000 Mark 65000 Paul 40000 Teddy 20000 Let us use ORDER BY clause along with GROUP BY clause as follows: sqlite> SELECT NAME, SUM(SALARY) FROM COMPANY GROUP BY NAME ORDER BY NAME DESC; This would produce the following result: NAME SUM(SALARY) ---------- ----------- Teddy 20000 Paul 40000 Mark 65000 Kim 45000
- 73. TUTORIALS POINT Simply Easy Learning James 20000 David 85000 Allen 15000
- 74. TUTORIALS POINT Simply Easy Learning SQLite Having Clause The HAVING clause enables you to specify conditions that filter which group results appear in the final results. The WHERE clause places conditions on the selected columns, whereas the HAVING clause places conditions on groups created by the GROUP BY clause. Syntax: The following is the position of the HAVING clause in a SELECT query: SELECT FROM WHERE GROUP BY HAVING ORDER BY The HAVING clause must follow the GROUP BY clause in a query and must also precede the ORDER BY clause if used. The following is the syntax of the SELECT statement, including the HAVING clause: SELECT column1, column2 FROM table1, table2 WHERE [ conditions ] GROUP BY column1, column2 HAVING [ conditions ] ORDER BY column1, column2 Example: Consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 CHAPTER 24
- 75. TUTORIALS POINT Simply Easy Learning 7 James 24 Houston 10000.0 8 Paul 24 Houston 20000.0 9 James 44 Norway 5000.0 10 James 45 Texas 5000.0 Following is the example, which would display record for which name count is less than 2: sqlite > SELECT * FROM COMPANY GROUP BY name HAVING count(name) < 2; This would produce the following result: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 2 Allen 25 Texas 15000 5 David 27 Texas 85000 6 Kim 22 South-Hall 45000 4 Mark 25 Rich-Mond 65000 3 Teddy 23 Norway 20000 Following is the example, which would display record for which name count is greater than 2: sqlite > SELECT * FROM COMPANY GROUP BY name HAVING count(name) > 2; This would produce the following result: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 10 James 45 Texas 5000
- 76. TUTORIALS POINT Simply Easy Learning SQLite Distinct Keyword The SQLite DISTINCT keyword is used in conjunction with SELECT statement to eliminate all the duplicate records and fetching only unique records. There may be a situation when you have multiple duplicate records in a table. While fetching such records, it makes more sense to fetch only unique records instead of fetching duplicate records. Syntax: The basic syntax of DISTINCT keyword to eliminate duplicate records is as follows: SELECT DISTINCT column1, column2,.....columnN FROM table_name WHERE [condition] Example: Consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 8 Paul 24 Houston 20000.0 9 James 44 Norway 5000.0 10 James 45 Texas 5000.0 First, let us see how the following SELECT query returns duplicate salary records: sqlite> SELECT name FROM COMPANY; This would produce the following result: NAME ---------- CHAPTER 25
- 77. TUTORIALS POINT Simply Easy Learning Paul Allen Teddy Mark David Kim James Paul James James Now, let us use DISTINCT keyword with the above SELECT query and see the result: sqlite> SELECT DISTINCT name FROM COMPANY; This would produce the following result, where we do not have any duplicate entry: NAME ---------- Paul Allen Teddy Mark David Kim James
- 78. TUTORIALS POINT Simply Easy Learning SQLite PRAGMA The SQLite PRAGMA command is a special command to be used to control various environmental variables and state flags within the SQLite environment. A PRAGMA value can be read and it can also be set based on requirements. Syntax: To query the current PRAGMA value, just provide the name of the pragma: PRAGMA pragma_name; To set a new value for PRAGMA, you will use the following syntax: PRAGMA pragma_name = value; The set mode can be either the name or the integer equivalent but the returned value will always be an integer. auto_vacuum Pragma The auto_vacuum pragma gets or sets the auto-vacuum mode. Following is the simple syntax: PRAGMA [database.]auto_vacuum; PRAGMA [database.]auto_vacuum = mode; Where mode can be any of the following: Pragma Value Description 0 or NONE Auto-vacuum is disabled. This is default mode which means that a database file will never shrink in size unless it is manually vacuumed using the VACUUM command. 1 or FULL Auto-vacuum is enabled and fully automatic which allows a database file to shrink as data is removed from the database. 2 or INCREMENTAL Auto-vacuum is enabled but must be manually activated. In this mode the reference data is maintained, but free pages are simply put on the free list. These pages can be recovered using the incremental_vacuum pragmaany time. CHAPTER 26
- 79. TUTORIALS POINT Simply Easy Learning cache_size Pragma The cache_size pragma can get or temporarily set the maximum size of the in-memory page cache. Following is the simple syntax: PRAGMA [database.]cache_size; PRAGMA [database.]cache_size = pages; The pages value represents the number of pages in the cache. The built-in page cache has a default size of 2,000 pages and a minimum size of 10 pages. case_sensitive_like Pragma The case_sensitive_like pragma controls the case-sensitivity of the built-in LIKE expression. By default, this pragma is false which means that the built-in LIKE operator ignores letter case. Following is the simple syntax: PRAGMA case_sensitive_like = [true|false]; There is no way to query for the current state of this pragma. count_changes Pragma The count_changes pragma gets or sets the return value of data manipulation statements such as INSERT, UPDATE and DELETE. Following is the simple syntax: PRAGMA count_changes; PRAGMA count_changes = [true|false]; By default, this pragma is false and these statements do not return anything. If set to true, each of the mentioned statement will return an one-column, one-row table consisting of a single integer value indicating impacted rows by the operation. database_list Pragma The database_list pragma will be used to list down all the databases attached. Following is the simple syntax: PRAGMA database_list; This pragma will return a three-column table with one row per open or attached database giving database sequence number, its name and file associated. encoding Pragma The encoding pragma controls how strings are encoded and stored in a database file. Following is the simple syntax: PRAGMA encoding; PRAGMA encoding = format; The format value can be one of UTF-8, UTF-16le, or UTF-16be. freelist_count Pragma The freelist_count pragma returns a single integer indicating how many database pages are currently marked as free and available. Following is the simple syntax: PRAGMA [database.]freelist_count;
- 80. TUTORIALS POINT Simply Easy Learning The format value can be one of UTF-8, UTF-16le, or UTF-16be. index_info Pragma The index_info pragma returns information about a database index. Following is the simple syntax: PRAGMA [database.]index_info( index_name ); The result set will contain one row for each column contained in the index giving column sequence, column index within table and column name. index_list Pragma The index_list pragma lists all of the indexes associated with a table. Following is the simple syntax: PRAGMA [database.]index_list( table_name ); The result set will contain one row for each index giving index sequence, index name and flag indicating whether index is unique or not. journal_mode Pragma The journal_mode pragma gets or sets the journal mode which controls how the journal file is stored and processed. Following is the simple syntax: PRAGMA journal_mode; PRAGMA journal_mode = mode; PRAGMA database.journal_mode; PRAGMA database.journal_mode = mode; There are five supported journal modes: Pragma Value Description DELETE This is default mode. Here at the conclusion of a transaction, the journal file is deleted. TRUNCATE The journal file is truncated to a length of zero bytes. PERSIST The journal file is left in place, but the header is overwritten to indicate the journal is no longer valid. MEMORY The journal record is held in memory, rather than on disk. OFF No journal record is kept. max_page_count Pragma The max_page_count pragma gets or sets the maximum allowed page count for a database. Following is the simple syntax: PRAGMA [database.]max_page_count; PRAGMA [database.]max_page_count = max_page; The default value is 1,073,741,823 which is one giga-page which means if the default 1 KB page size, this allows databases to grow up to one terabyte.
- 81. TUTORIALS POINT Simply Easy Learning page_count Pragma The page_count pragma returns the current number of pages in database. Following is the simple syntax: PRAGMA [database.]page_count; The size of the database file should be page_count * page_size. page_size Pragma The page_size pragma gets or sets the size of the database pages. Following is the simple syntax: PRAGMA [database.]page_size; PRAGMA [database.]page_size = bytes; By default, the allowed sizes are 512, 1024, 2048, 4096, 8192, 16384, and 32768 bytes. The only way to alter the page size on an existing database is to set the page size and then immediately VACUUM the database. parser_trace Pragma The parser_trace pragma controls printing the debugging state as it parses SQL commands. Following is the simple syntax: PRAGMA parser_trace = [true|false]; By default, it is set to false but when enabled by setting it to true, the SQL parser will print its state as it parses SQL commands. recursive_triggers Pragma The recursive_triggers pragma gets or sets the recursive trigger functionality. If recursive triggers are not enabled, a trigger action will not fire another trigger. Following is the simple syntax: PRAGMA recursive_triggers; PRAGMA recursive_triggers = [true|false]; schema_version Pragma The schema_version pragma gets or sets the schema version value that is stored in the database header. Following is the simple syntax: PRAGMA [database.]schema_version; PRAGMA [database.]schema_version = number; This is a 32-bit signed integer value that keeps track of schema changes. Whenever a schema-altering command is executed (like, CREATE... or DROP...), this value is incremented. secure_delete Pragma The secure_delete pragma is used to control how content is deleted from the database. Following is the simple syntax: PRAGMA secure_delete; PRAGMA secure_delete = [true|false]; PRAGMA database.secure_delete; PRAGMA database.secure_delete = [true|false];
- 82. TUTORIALS POINT Simply Easy Learning The default value for the secure delete flag is normally off, but this can be changed with the SQLITE_SECURE_DELETE build option. sql_trace Pragma The sql_trace pragma is used to dump SQL trace results to the screen. Following is the simple syntax: PRAGMA sql_trace; PRAGMA sql_trace = [true|false]; SQLite must be compiled with the SQLITE_DEBUG directive for this pragma to be included. synchronous Pragma The synchronous pragma gets or sets the current disk synchronization mode which controls how aggressively SQLite will write data all the way out to physical storage. Following is the simple syntax: PRAGMA [database.]synchronous; PRAGMA [database.]synchronous = mode; SQLite supports the following synchronisation modes: Pragma Value Description 0 or OFF No syncs at all 1 or NORMAL Sync after each sequence of critical disk operations 2 or FULL Sync after each critical disk operation temp_store Pragma The temp_store pragma gets or sets the storage mode used by temporary database files. Following is the simple syntax: PRAGMA temp_store; PRAGMA temp_store = mode; SQLite supports the following storage modes: Pragma Value Description 0 or DEFAULT Use compile-time default. Normally FILE. 1 or FILE Use file-based storage. 2 or MEMORY Use memory-based storage. temp_store_directory Pragma The temp_store_directory pragma gets or sets the location used for temporary database files. Following is the simple syntax: PRAGMA temp_store_directory; PRAGMA temp_store_directory = 'directory_path';
- 83. TUTORIALS POINT Simply Easy Learning user_version Pragma The user_version pragma gets or sets the user-defined version value that is stored in the database header. Following is simple syntax: PRAGMA [database.]user_version; PRAGMA [database.]user_version = number; This is a 32-bit signed integer value, which can be set by the developer for version tracking purpose. writable_schema Pragma The writable_schema pragma gets or sets the ability to modify system tables. Following is the simple syntax: PRAGMA writable_schema; PRAGMA writable_schema = [true|false]; If this pragma is set, tables that start with sqlite_ can be created and modified, including the sqlite_master table. Be careful while using pragma because it can lead to complete database corruption.
- 84. TUTORIALS POINT Simply Easy Learning SQLite Constraints Constraints are the rules enforced on data columns on table. These are used to limit the type of data that can go into a table. This ensures the accuracy and reliability of the data in the database. Constraints could be column level or table level. Column level constraints are applied only to one column where as table level constraints are applied to the whole table. Following are commonly used constraints available in SQLite. NOT NULL Constraint: Ensures that a column cannot have NULL value. DEFAULT Constraint : Provides a default value for a column when none is specified. UNIQUE Constraint: Ensures that all values in a column are different. PRIMARY Key: Uniquely identified each rows/records in a database table. CHECK Constraint: The CHECK constraint ensures that all values in a column satisfy certain conditions. NOT NULL Constraint By default, a column can hold NULL values. If you do not want a column to have a NULL value, then you need to define such constraint on this column specifying that NULL is now not allowed for that column. A NULL is not the same as no data, rather, it represents unknown data. EXAMPLE: For example, the following SQLite statement creates a new table called COMPANY and adds five columns, three of which, ID and NAME and AGE, specify not to accept NULLs: CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL ); DEFAULT Constraint The DEFAULT constraint provides a default value to a column when the INSERT INTO statement does not provide a specific value. CHAPTER 27
- 85. TUTORIALS POINT Simply Easy Learning EXAMPLE: For example, the following SQLite statement creates a new table called COMPANY and adds five columns. Here, SALARY column is set to 5000.00 by default, so in case INSERT INTO statement does not provide a value for this column, then by default, this column would be set to 5000.00. CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL DEFAULT 50000.00 ); UNIQUE Constraint The UNIQUE Constraint prevents two records from having identical values in a particular column. In the COMPANY table, for example, you might want to prevent two or more people from having identical age. EXAMPLE: For example, the following SQLite statement creates a new table called COMPANY and adds five columns. Here, AGE column is set to UNIQUE, so that you can not have two records with same age: CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL UNIQUE, ADDRESS CHAR(50), SALARY REAL DEFAULT 50000.00 ); PRIMARY KEY Constraint The PRIMARY KEY constraint uniquely identifies each record in a database table. There can be more UNIQUE columns, but only one primary key in a table. Primary keys are important when designing the database tables. Primary keys are unique ids. We use them to refer to table rows. Primary keys become foreign keys in other tables, when creating relations among tables. Due to a 'longstanding coding oversight', primary keys can be NULL in SQLite. This is not the case with other databases. A primary key is a field in a table which uniquely identifies the each rows/records in a database table. Primary keys must contain unique values. A primary key column cannot have NULL values. A table can have only one primary key which may consist of single or multiple fields. When multiple fields are used as a primary key, they are called a composite key. If a table has a primary key defined on any field(s), then you can not have two records having the same value of that field(s). EXAMPLE: You already have seen various examples above where we have created COMAPNY table with ID as primary key: CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL,
- 86. TUTORIALS POINT Simply Easy Learning NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL ); CHECK Constraint The CHECK Constraint enables a condition to check the value being entered into a record. If the condition evaluates to false, the record violates the constraint and isn't entered into the table. EXAMPLE: For example, the following SQLite creates a new table called COMPANY and adds five columns. Here, we add a CHECK with SALARY column, so that you can not have any SALARY Zero: CREATE TABLE COMPANY3( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL CHECK(SALARY > 0) ); Dropping Constraints: SQLite supports a limited subset of ALTER TABLE. The ALTER TABLE command in SQLite allows the user to rename a table or to add a new column to an existing table. It is not possible to rename a column, remove a column, or add or remove constraints from a table.
- 87. TUTORIALS POINT Simply Easy Learning SQLite Joins The SQLite Joins clause is used to combine records from two or more tables in a database. A JOIN is a means for combining fields from two tables by using values common to each. SQL defines three major types of joins: The CROSS JOIN The INNER JOIN The OUTER JOIN Before we proceed, let's consider two tables COMPANY and DEPARTMENT. We already have seen INSERT statements to populate COMPANY table. So just let's assume the list of records available in COMPANY table: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Another table is DEPARTMENT has the following definition: CREATE TABLE DEPARTMENT( ID INT PRIMARY KEY NOT NULL, DEPT CHAR(50) NOT NULL, EMP_ID INT NOT NULL ); Here is the list of INSERT statements to populate DEPARTMENT table: INSERT INTO DEPARTMENT (ID, DEPT, EMP_ID) VALUES (1, 'IT Billing', 1 ); INSERT INTO DEPARTMENT (ID, DEPT, EMP_ID) VALUES (2, 'Engineering', 2 ); CHAPTER 28
- 88. TUTORIALS POINT Simply Easy Learning INSERT INTO DEPARTMENT (ID, DEPT, EMP_ID) VALUES (3, 'Finance', 7 ); Finally, we have the following list of records available in DEPARTMENT table: ID DEPT EMP_ID ---------- ---------- ---------- 1 IT Billing 1 2 Engineerin 2 3 Finance 7 The CROSS JOIN A CROSS JOIN matches every row of the first table with every row of the second table. If the input tables have x and y columns, respectively, the resulting table will have x+y columns. Because CROSS JOINs have the potential to generate extremely large tables, care must be taken to only use them when appropriate. Following is the syntax of CROSS JOIN: SELECT ... FROM table1 CROSS JOIN table2 ... Based on the above tables, we can write a cross join as follows: sqlite> SELECT EMP_ID, NAME, DEPT FROM COMPANY CROSS JOIN DEPARTMENT; Above query will produce the following result: EMP_ID NAME DEPT ---------- ---------- ---------- 1 Paul IT Billing 2 Paul Engineerin 7 Paul Finance 1 Allen IT Billing 2 Allen Engineerin 7 Allen Finance 1 Teddy IT Billing 2 Teddy Engineerin 7 Teddy Finance 1 Mark IT Billing 2 Mark Engineerin 7 Mark Finance 1 David IT Billing 2 David Engineerin 7 David Finance 1 Kim IT Billing 2 Kim Engineerin 7 Kim Finance 1 James IT Billing 2 James Engineerin 7 James Finance The INNER JOIN A INNER JOIN creates a new result table by combining column values of two tables (table1 and table2) based upon the join-predicate. The query compares each row of table1 with each row of table2 to find all pairs of rows, which satisfy the join-predicate. When the join-predicate is satisfied, column values for each matched pair of rows of A and B are combined into a result row.
- 89. TUTORIALS POINT Simply Easy Learning An INNER JOIN is the most common type of join and is the default type of join. You can use INNER keyword optionally. Following is the syntax of INNER JOIN: SELECT ... FROM table1 [INNER] JOIN table2 ON conditional_expression ... To avoid redundancy and keep the phrasing shorter, INNER JOIN conditions can be declared with a USING expression. This expression specifies a list of one or more columns: SELECT ... FROM table1 JOIN table2 USING ( column1 ,... ) ... A NATURAL JOIN is similar to a JOIN...USING, only it automatically tests for equality between the values of every column that exists in both tables: SELECT ... FROM table1 NATURAL JOIN table2... Based on the above tables, we can write a INNER JOIN as follows: sqlite> SELECT EMP_ID, NAME, DEPT FROM COMPANY INNER JOIN DEPARTMENT ON COMPANY.ID = DEPARTMENT.EMP_ID; Above query will produce the following result: EMP_ID NAME DEPT ---------- ---------- ---------- 1 Paul IT Billing 2 Allen Engineerin 7 James Finance The OUTER JOIN The OUTER JOIN is an extension of the INNER JOIN. Though SQL standard defines three types of OUTER JOINs: LEFT, RIGHT and FULL but SQLite only supports the LEFT OUTER JOIN. The OUTER JOINs have a condition that is identical to INNER JOINs, expressed using an ON, USING or NATURAL keyword. The initial results table is calculated the same way. Once the primary JOIN is calculated, an OUTER join will take any unjoined rows from one or both tables, pad them out with NULLs, and append them to the resulting table. Following is the syntax of LEFT OUTER JOIN: SELECT ... FROM table1 LEFT OUTER JOIN table2 ON conditional_expression ... To avoid redundancy and keep the phrasing shorter, OUTER JOIN conditions can be declared with a USING expression. This expression specifies a list of one or more columns: SELECT ... FROM table1 LEFT OUTER JOIN table2 USING ( column1 ,... ) ... Based on the above tables, we can write a inner join as follows: sqlite> SELECT EMP_ID, NAME, DEPT FROM COMPANY LEFT OUTER JOIN DEPARTMENT ON COMPANY.ID = DEPARTMENT.EMP_ID; Above query will produce the following result: EMP_ID NAME DEPT ---------- ---------- ---------- 1 Paul IT Billing 2 Allen Engineerin
- 90. TUTORIALS POINT Simply Easy Learning Teddy Mark David Kim 7 James Finance
- 91. TUTORIALS POINT Simply Easy Learning SQLite UNIONS Clause The SQLite UNION clause/operator is used to combine the results of two or more SELECT statements without returning any duplicate rows. To use UNION, each SELECT must have the same number of columns selected, the same number of column expressions, the same data type, and have them in the same order, but they do not have to be the same length. Syntax: The basic syntax of UNION is as follows: SELECT column1 [, column2 ] FROM table1 [, table2 ] [WHERE condition] UNION SELECT column1 [, column2 ] FROM table1 [, table2 ] [WHERE condition] Here given condition could be any given expression based on your requirement. Example: The tables COMPANY and DEPARTMENT are shown here: COMPANY TABLE This is the file to create COMPANY table and to populate it with 7 records. -- Just copy and past them on sqlite> prompt. DROP TABLE COMPANY; CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL ); CHAPTER 29
- 92. TUTORIALS POINT Simply Easy Learning INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (1, 'Paul', 32, 'California', 20000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (2, 'Allen', 25, 'Texas', 15000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (3, 'Teddy', 23, 'Norway', 20000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (5, 'David', 27, 'Texas', 85000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (6, 'Kim', 22, 'South-Hall', 45000.00 ); INSERT INTO COMPANY VALUES (7, 'James', 24, 'Houston', 10000.00 ); DEPARTMENT TABLE -- This is the file to create DEPARTMENT table and to populate it with 7 records. -- Just copy and past them on sqlite> prompt. DROP TABLE DEPARTMENT; CREATE TABLE DEPARTMENT( ID INT PRIMARY KEY NOT NULL, DEPT CHAR(50) NOT NULL, EMP_ID INT NOT NULL ); INSERT INTO DEPARTMENT(ID,DEPT,EMP_ID) VALUES (1, 'IT Billing', 1); INSERT INTO DEPARTMENT(ID,DEPT,EMP_ID) VALUES (2, 'Engineering', 2); INSERT INTO DEPARTMENT(ID,DEPT,EMP_ID) VALUES (3, 'Finance',7); INSERT INTO DEPARTMENT(ID,DEPT,EMP_ID) VALUES (4, 'Engineering',3); INSERT INTO DEPARTMENT(ID,DEPT,EMP_ID) VALUES (5, 'Finance', 4); INSERT INTO DEPARTMENT(ID,DEPT,EMP_ID) VALUES (6, 'Engineering', 5); INSERT INTO DEPARTMENT(ID,DEPT,EMP_ID) VALUES (7, 'Finance', 6); Consider following two tables, (a) COMPANY table is as follows: sqlite> select * from COMPANY; ID NAME AGE ADDRESS SALARY ---------- -------------------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0
- 93. TUTORIALS POINT Simply Easy Learning 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 (b) Another table is DEPARTMENT as follows: ID DEPT EMP_ID ---------- -------------------- ---------- 1 IT Billing 1 2 Engineering 2 3 Finance 7 4 Engineering 3 5 Finance 4 6 Engineering 5 7 Finance 6 Now, let us join these two tables using SELECT statement along with UNION clause as follows: sqlite> SELECT EMP_ID, NAME, DEPT FROM COMPANY INNER JOIN DEPARTMENT ON COMPANY.ID = DEPARTMENT.EMP_ID UNION SELECT EMP_ID, NAME, DEPT FROM COMPANY LEFT OUTER JOIN DEPARTMENT ON COMPANY.ID = DEPARTMENT.EMP_ID; This would produce the following result: EMP_ID NAME DEPT ---------- -------------------- ---------- 1 Paul IT Billing 2 Allen Engineerin 3 Teddy Engineerin 4 Mark Finance 5 David Engineerin 6 Kim Finance 7 James Finance The UNION ALL Clause: The UNION ALL operator is used to combine the results of two SELECT statements including duplicate rows. The same rules that apply to UNION apply to the UNION ALL operator as well. Syntax: The basic syntax of UNION ALL is as follows: SELECT column1 [, column2 ] FROM table1 [, table2 ] [WHERE condition] UNION ALL SELECT column1 [, column2 ] FROM table1 [, table2 ] [WHERE condition] Here given condition could be any given expression based on your requirement.
- 94. TUTORIALS POINT Simply Easy Learning Example: Now, let us join above-mentioned two tables in our SELECT statement as follows: sqlite> SELECT EMP_ID, NAME, DEPT FROM COMPANY INNER JOIN DEPARTMENT ON COMPANY.ID = DEPARTMENT.EMP_ID UNION ALL SELECT EMP_ID, NAME, DEPT FROM COMPANY LEFT OUTER JOIN DEPARTMENT ON COMPANY.ID = DEPARTMENT.EMP_ID; This would produce the following result: EMP_ID NAME DEPT ---------- -------------------- ---------- 1 Paul IT Billing 2 Allen Engineerin 3 Teddy Engineerin 4 Mark Finance 5 David Engineerin 6 Kim Finance 7 James Finance 1 Paul IT Billing 2 Allen Engineerin 3 Teddy Engineerin 4 Mark Finance 5 David Engineerin 6 Kim Finance 7 James Finance
- 95. TUTORIALS POINT Simply Easy Learning SQLite NULL Values The SQLite NULL is the term used to represent a missing value. A NULL value in a table is a value in a field that appears to be blank. A field with a NULL value is a field with no value. It is very important to understand that a NULL value is different than a zero value or a field that contains spaces. Syntax: The basic syntax of using NULL while creating a table: SQLite> CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL ); Here, NOT NULL signifies that column should always accept an explicit value of the given data type. There are two columns where we did not use NOT NULL which means these columns could be NULL. A field with a NULL value is one that has been left blank during record creation. Example: The NULL value can cause problems when selecting data, however, because when comparing an unknown value to any other value, the result is always unknown and not included in the final results. Consider the following table, COMPANY having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Let us use UPDATE statement to set few nullable values as NULL as follows: CHAPTER 30
- 96. TUTORIALS POINT Simply Easy Learning sqlite> UPDATE COMPANY SET ADDRESS = NULL, SALARY = NULL where ID IN(6,7); Now, COMPANY table should have the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 7 James 24 Next, let us see the usage of IS NOT NULL operator to list down all the records where SALARY is not NULL: sqlite> SELECT ID, NAME, AGE, ADDRESS, SALARY FROM COMPANY WHERE SALARY IS NOT NULL; Above SQLite statement will produce the following result: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 Following is the usage of IS NULL operator, which will list down all the records where SALARY is NULL: sqlite> SELECT ID, NAME, AGE, ADDRESS, SALARY FROM COMPANY WHERE SALARY IS NULL; Above SQLite statement will produce the following result: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 6 Kim 22 7 James 24
- 97. TUTORIALS POINT Simply Easy Learning SQLite ALIAS Syntax You can rename a table or a column temporarily by giving another name, which is known as ALIAS. The use of table aliases means to rename a table in a particular SQLite statement. Renaming is a temporary change and the actual table name does not change in the database. The column aliases are used to rename a table's columns for the purpose of a particular SQLite query. Syntax: The basic syntax of table alias is as follows: SELECT column1, column2.... FROM table_name AS alias_name WHERE [condition]; The basic syntax of column alias is as follows: SELECT column_name AS alias_name FROM table_name WHERE [condition]; Example: Consider the following two tables, (a) COMPANY table is as follows: sqlite> select * from COMPANY; ID NAME AGE ADDRESS SALARY ---------- -------------------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 (b) Another table is DEPARTMENT as follows: ID DEPT EMP_ID ---------- -------------------- ---------- CHAPTER 31
- 98. TUTORIALS POINT Simply Easy Learning 1 IT Billing 1 2 Engineering 2 3 Finance 7 4 Engineering 3 5 Finance 4 6 Engineering 5 7 Finance 6 Now, following is the usage of TABLE ALIAS where we use C and D as aliases for COMPANY and DEPARTMENT tables respectively: sqlite> SELECT C.ID, C.NAME, C.AGE, D.DEPT FROM COMPANY AS C, DEPARTMENT AS D WHERE C.ID = D.EMP_ID; Above SQLite statement will produce the following result: ID NAME AGE DEPT ---------- ---------- ---------- ---------- 1 Paul 32 IT Billing 2 Allen 25 Engineerin 3 Teddy 23 Engineerin 4 Mark 25 Finance 5 David 27 Engineerin 6 Kim 22 Finance 7 James 24 Finance Let us see an example for the usage of COLUMN ALIAS where COMPANY_ID is an alias of ID column and COMPANY_NAME is an alias of name column: sqlite> SELECT C.ID AS COMPANY_ID, C.NAME AS COMPANY_NAME, C.AGE, D.DEPT FROM COMPANY AS C, DEPARTMENT AS D WHERE C.ID = D.EMP_ID; Above SQLite statement will produce the following result: COMPANY_ID COMPANY_NAME AGE DEPT ---------- ------------ ---------- ---------- 1 Paul 32 IT Billing 2 Allen 25 Engineerin 3 Teddy 23 Engineerin 4 Mark 25 Finance 5 David 27 Engineerin 6 Kim 22 Finance 7 James 24 Finance
- 99. TUTORIALS POINT Simply Easy Learning SQLite Triggers SQLite Triggers are database callback functions, which are automatically performed/invoked when a specified database event occurs. Following are the important points about SQLite triggers: SQLite trigger may be specified to fire whenever a DELETE, INSERT or UPDATE of a particular database table occurs or whenever an UPDATE occurs on on one or more specified columns of a table. At this time, SQLite supports only FOR EACH ROW triggers, not FOR EACH STATEMENT triggers. Hence, explicitly specifying FOR EACH ROW is optional. Both the WHEN clause and the trigger actions may access elements of the row being inserted, deleted or updated using references of the form NEW.column-name and OLD.column-name, where column-name is the name of a column from the table that the trigger is associated with. If a WHEN clause is supplied, the SQL statements specified are only executed for rows for which the WHEN clause is true. If no WHEN clause is supplied, the SQL statements are executed for all rows. The BEFORE or AFTER keyword determines when the trigger actions will be executed relative to the insertion, modification or removal of the associated row. Triggers are automatically dropped when the table that they are associated with is dropped. The table to be modified must exist in the same database as the table or view to which the trigger is attached and one must use just tablename not database.tablename. A special SQL function RAISE() may be used within a trigger-program to raise an exception. Syntax: The basic syntax of creating a trigger is as follows: CREATE TRIGGER trigger_name [BEFORE|AFTER] event_name ON table_name BEGIN -- Trigger logic goes here.... END; Here, event_name could be INSERT, DELETE, and UPDATE database operation on the mentioned table table_name. You can optionally specify FOR EACH ROW after table name. CHAPTER 32
- 100. TUTORIALS POINT Simply Easy Learning Following is the syntax of creating a trigger on an UPDATE operation on one or more specified columns of a table as follows: CREATE TRIGGER trigger_name [BEFORE|AFTER] UPDATE OF column_name ON table_name BEGIN -- Trigger logic goes here.... END; Example Let us consider a case where we want to keep audit trial for every record being inserted in COMPANY table, which we create newly as follows (Drop COMPANY table if you already have it): sqlite> CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL ); To keep audit trial, we will create a new table called AUDIT where log messages will be inserted whenever there is an entry in COMPANY table for a new record: sqlite> CREATE TABLE AUDIT( EMP_ID INT NOT NULL, ENTRY_DATE TEXT NOT NULL ); Here, ID is the AUDIT record ID, and EMP_ID is the ID which will come from COMPANY table and DATE will keep timestamp when the record will be created in COMPANY table. So now let's create a trigger on COMPANY table as follows: sqlite> CREATE TRIGGER audit_log AFTER INSERT ON COMPANY BEGIN INSERT INTO AUDIT(EMP_ID, ENTRY_DATE) VALUES (new.ID, datetime('now')); END; Now, we will start actual work, let's start inserting record in COMPANY table which should result in creating an audit log record in AUDIT table. So let's create one record in COMPANY table as follows: sqlite> INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (1, 'Paul', 32, 'California', 20000.00 ); This will create one record in COMPANY table, which is as follows: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 Same time, one record will be create in AUDIT table. This record is the result of a trigger, which we have created on INSERT operation on COMPANY table. Similar way, you can create your triggers on UPDATE and DELETE operations based on your requirements. EMP_ID ENTRY_DATE ---------- ------------------- 1 2013-04-05 06:26:00
- 101. TUTORIALS POINT Simply Easy Learning Listing TRIGGERS You can list down all the triggers from sqlite_master table as follows: sqlite> SELECT name FROM sqlite_master WHERE type = 'trigger'; Above SQLite statement will list down only one entry as follows: name ---------- audit_log If you want to list down triggers on a particular table, then use AND clause with table name as follows: sqlite> SELECT name FROM sqlite_master WHERE type = 'trigger' AND tbl_name = 'COMPANY'; Above SQLite statement will also list down only one entry as follows: name ---------- audit_log Dropping TRIGGERS Following is the DROP command, which can be used to drop an existing trigger: sqlite> DROP TRIGGER trigger_name;
- 102. TUTORIALS POINT Simply Easy Learning SQLite Indexes Indexes are special lookup tables that the database search engine can use to speed up data retrieval. Simply put, an index is a pointer to data in a table. An index in a database is very similar to an index in the back of a book. For example, if you want to reference all pages in a book that discuss a certain topic, you first refer to the index, which lists all topics alphabetically and are then referred to one or more specific page numbers. An index helps speed up SELECT queries and WHERE clauses, but it slows down data input, with UPDATE and INSERT statements. Indexes can be created or dropped with no effect on the data. Creating an index involves the CREATE INDEX statement, which allows you to name the index, to specify the table and which column or columns to index, and to indicate whether the index is in ascending or descending order. Indexes can also be unique, similar to the UNIQUE constraint, in that the index prevents duplicate entries in the column or combination of columns on which there's an index. The CREATE INDEX Command: The basic syntax of CREATE INDEX is as follows: CREATE INDEX index_name ON table_name; Single-Column Indexes: A single-column index is one that is created based on only one table column. The basic syntax is as follows: CREATE INDEX index_name ON table_name (column_name); Unique Indexes: Unique indexes are used not only for performance, but also for data integrity. A unique index does not allow any duplicate values to be inserted into the table. The basic syntax is as follows: CREATE INDEX index_name CHAPTER 33
- 103. TUTORIALS POINT Simply Easy Learning on table_name (column_name); Composite Indexes: A composite index is an index on two or more columns of a table. The basic syntax is as follows: CREATE INDEX index_name on table_name (column1, column2); Whether to create a single-column index or a composite index, take into consideration the column(s) that you may use very frequently in a query's WHERE clause as filter conditions. Should there be only one column used, a single-column index should be the choice. Should there be two or more columns that are frequently used in the WHERE clause as filters, the composite index would be the best choice. Implicit Indexes: Implicit indexes are indexes that are automatically created by the database server when an object is created. Indexes are automatically created for primary key constraints and unique constraints. Example Following is an example where we will create an index on COMPANY table for salary column: sqlite> CREATE INDEX salary_index ON COMPANY (salary); Now, let's list down all the indices available on COMPANY table using .indices command as follows: sqlite> .indices COMPANY This will produce the following result, where sqlite_autoindex_COMPANY_1 is an implicit index, which got created when table itself was created. salary_index sqlite_autoindex_COMPANY_1 You can list down all the indexes database wide as follows: sqlite> SELECT * FROM sqlite_master WHERE type = 'index'; The DROP INDEX Command: An index can be dropped using SQLite DROP command. Care should be taken when dropping an index because performance may be slowed or improved. The basic syntax is as follows: DROP INDEX index_name; You can use following statement to delete previously created index: sqlite> DROP INDEX salary_index;
- 104. TUTORIALS POINT Simply Easy Learning When should indexes be avoided? Although indexes are intended to enhance a database's performance, there are times when they should be avoided. The following guidelines indicate when the use of an index should be reconsidered: Indexes should not be used on small tables. Tables that have frequent, large batch update or insert operations. Indexes should not be used on columns that contain a high number of NULL values. Columns that are frequently manipulated should not be indexed.
- 105. TUTORIALS POINT Simply Easy Learning SQLite Indexed By The "INDEXED BY index-name" clause specifies that the named index must be used in order to look up values on the preceding table. If index-name does not exist or cannot be used for the query, then the preparation of the SQLite statement fails. The "NOT INDEXED" clause specifies that no index shall be used when accessing the preceding table, including implied indices create by UNIQUE and PRIMARY KEY constraints. However, the INTEGER PRIMARY KEY can still be used to look up entries even when "NOT INDEXED" is specified. Syntax Following is the syntax for INDEXED BY clause and it can be used with DELETE, UPDATE or SELECT statement: SELECT|DELETE|UPDATE column1, column2... INDEXED BY (index_name) table_name WHERE (CONDITION); Example COMPANY Table: -- This is the file to create COMPANY table and to populate it with 7 records. -- Just copy and past them on sqlite> prompt. DROP TABLE COMPANY; CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (1, 'Paul', 32, 'California', 20000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (2, 'Allen', 25, 'Texas', 15000.00 ); CHAPTER 34
- 106. TUTORIALS POINT Simply Easy Learning INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (3, 'Teddy', 23, 'Norway', 20000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (5, 'David', 27, 'Texas', 85000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (6, 'Kim', 22, 'South-Hall', 45000.00 ); INSERT INTO COMPANY VALUES (7, 'James', 24, 'Houston', 10000.00 ); Consider above table COMPANY we will create an index and use it for performing INDEXED BY operation. sqlite> CREATE INDEX salary_index ON COMPANY(salary); sqlite> Now selecting the data from table COMPANY you can use INDEXED BY clause as follows: sqlite> SELECT * FROM COMPANY INDEXED BY salary_index WHERE salary > 5000; Kindly note that though SQLite specification talks about the above-mentioned Syntax forINDEXED BY clause but I tried all the way to make INDEXED BY work on my installation but it did not work. If you found a solution kindly share it at [email protected].
- 107. TUTORIALS POINT Simply Easy Learning SQLite Alter Command The SQLite ALTER TABLE command modifies an existing table without performing a full dump and reload of the data. You can rename a table using ALTER TABLE statement and additional columns can be added in an existing table using ALTER TABLE statement. There is no other operation supported by ALTER TABLE command in SQLite except renaming a table and adding a column in existing table. Syntax: The basic syntax of ALTER TABLE to RENAME an existing table is as follows: ALTER TABLE database_name.table_name RENAME TO new_table_name; The basic syntax of ALTER TABLE to add a new column in an existing table is as follows: ALTER TABLE database_name.table_name ADD COLUMN column_def...; Example: Consider our COMPANY table has the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Now, let's try to rename this table using ALTER TABLE statement as follows: sqlite> ALTER TABLE COMPANY RENAME TO OLD_COMPANY; CHAPTER 35
- 108. TUTORIALS POINT Simply Easy Learning Above SQLite statement will rename COMPANY table to OLD_COMPANY. Now, let's try to add a new column in OLD_COMPANY table as follows: sqlite> ALTER TABLE OLD_COMPANY ADD COLUMN SEX char(1); Now, COMPANY table is changed and following would be output from SELECT statement: ID NAME AGE ADDRESS SALARY SEX ---------- ---------- ---------- ---------- ---------- --- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 It should be noted that newly added column is filled with NULL values.
- 109. TUTORIALS POINT Simply Easy Learning SQLite Truncate Table Unfortunately, we do not have TRUNCATE TABLE command in SQLite but you can use SQLite DELETE command to delete complete data from an existing table, though it is recommended to use DROP TABLE command to drop complete table and re-create it once again. Syntax: The basic syntax of DELETE command is as follows: sqlite> DELETE FROM table_name; The basic syntax of DROP TABLE is as follows: sqlite> DROP TABLE table_name; If you are using DELETE TABLE command to delete all the records, it is recommended to useVACUUM command to clear unused space. Example: Consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Following is the example to truncate the above table: SQLite> DELETE FROM COMPANY; SQLite> VACUUM; Now, COMPANY table is truncated completely and nothing would be output from SELECT statement: CHAPTER 36
- 110. TUTORIALS POINT Simply Easy Learning SQLite Views Aview is nothing more than a SQLite statement that is stored in the database with an associated name. A view is actually a composition of a table in the form of a predefined SQLite query. A view can contain all rows of a table or selected rows from one or more tables. A view can be created from one or many tables which depends on the written SQLite query to create a view. Views which are kind of virtual tables, allow users to do the following: Structure data in a way that users or classes of users find natural or intuitive. Restrict access to the data such that a user can only see limited data instead of complete table. Summarize data from various tables which can be used to generate reports. SQLite views are read-only and so you may not execute a DELETE, INSERT or UPDATE statement on a view. But you can create a trigger on a view that fires on an attempt to DELETE, INSERT or UPDATE a view and do what you need in the body of the trigger. Creating Views: The SQLite views are created using the CREATE VIEW statement. The SQLIte views can be created from a single table, multiple tables, or another view. The basic CREATE VIEW syntax is as follows: CREATE [TEMP | TEMPORARY] VIEW view_name AS SELECT column1, column2..... FROM table_name WHERE [condition]; You can include multiple tables in your SELECT statement in very similar way as you use them in normal SQL SELECT query. If the optional TEMP or TEMPORARY keyword is present, the view will be created in the temp database. Example: Consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- CHAPTER 37
- 111. TUTORIALS POINT Simply Easy Learning 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Now, following is an example to create a view from COMPANY table. This view would be used to have only few columns from COMPANY table: sqlite> CREATE VIEW COMPANY_VIEW AS SELECT ID, NAME, AGE FROM COMPANY; Now, you can query COMPANY_VIEW in similar way as you query an actual table. Following is the example: sqlite> SELECT * FROM COMPANY_VIEW; This would produce the following result: ID NAME AGE ---------- ---------- ---------- 1 Paul 32 2 Allen 25 3 Teddy 23 4 Mark 25 5 David 27 6 Kim 22 7 James 24 Dropping Views: To drop a view, simply use the DROP VIEW statement with the view_name. The basic DROP VIEW syntax is as follows: sqlite> DROP VIEW view_name; Following command will delete COMPANY_VIEW view, which we created in the last section: sqlite> DROP VIEW COMPANY_VIEW;
- 112. TUTORIALS POINT Simply Easy Learning SQLite TRANSACTIONS Atransaction is a unit of work that is performed against a database. Transactions are units or sequences of work accomplished in a logical order, whether in a manual fashion by a user or automatically by some sort of a database program. A transaction is the propagation of one or more changes to the database. For example, if you are creating a record or updating a record or deleting a record from the table. then you are performing transaction on the table. It is important to control transactions to ensure data integrity and to handle database errors. Practically, you will club many SQLite queries into a group and you will execute all of them together as part of a transaction. Properties of Transactions: Transactions have the following four standard properties, usually referred to by the acronym ACID: Atomicity: ensures that all operations within the work unit are completed successfully; otherwise, the transaction is aborted at the point of failure and previous operations are rolled back to their former state. Consistency: ensures that the database properly changes states upon a successfully committed transaction. Isolation: enables transactions to operate independently of and transparent to each other. Durability: ensures that the result or effect of a committed transaction persists in case of a system failure. Transaction Control: There are the following commands used to control transactions: BEGIN TRANSACTION: to start a transaction. COMMIT: to save the changes, alternatively you can use END TRANSACTION command. ROLLBACK: to rollback the changes. Transactional control commands are only used with the DML commands INSERT, UPDATE and DELETE. They can not be used while creating tables or dropping them because these operations are automatically committed in the database. CHAPTER 38
- 113. TUTORIALS POINT Simply Easy Learning The BEGIN TRANSACTION Command: Transactions can be started using BEGIN TRANSACTION or simply BEGIN command. Such transactions usually persist until the next COMMIT or ROLLBACK command encountered. But a transaction will also ROLLBACK if the database is closed or if an error occurs. Following is the simple syntax to start a transaction: BEGIN; or BEGIN TRANSACTION; The COMMIT Command: The COMMIT command is the transactional command used to save changes invoked by a transaction to the database. The COMMIT command saves all transactions to the database since the last COMMIT or ROLLBACK command. The syntax for COMMIT command is as follows: COMMIT; or END TRANSACTION; The ROLLBACK Command: The ROLLBACK command is the transactional command used to undo transactions that have not already been saved to the database. The ROLLBACK command can only be used to undo transactions since the last COMMIT or ROLLBACK command was issued. The syntax for ROLLBACK command is as follows: ROLLBACK; Example: Consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Now, let's start a transaction and delete records from the table having age = 25 and finally we use ROLLBACK command to undo all the changes.
- 114. TUTORIALS POINT Simply Easy Learning sqlite> BEGIN; sqlite> DELETE FROM COMPANY WHERE AGE = 25; sqlite> ROLLBACK; If you will check, COMPANY table is still having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Now, let's start another transaction and delete records from the table having age = 25 and finally we use COMMIT command to commit all the changes. sqlite> BEGIN; sqlite> DELETE FROM COMPANY WHERE AGE = 25; sqlite> COMMIT; If you will check, COMPANY table is still having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 3 Teddy 23 Norway 20000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0
- 115. TUTORIALS POINT Simply Easy Learning SQLite Sub Queries ASubquery or Inner query or Nested query is a query within another SQLite query and embedded within the WHERE clause. A subquery is used to return data that will be used in the main query as a condition to further restrict the data to be retrieved. Subqueries can be used with the SELECT, INSERT, UPDATE and DELETE statements along with the operators like =, <, >, >=, <=, IN, BETWEEN etc. There are a few rules that subqueries must follow: Subqueries must be enclosed within parentheses. A subquery can have only one column in the SELECT clause, unless multiple columns are in the main query for the subquery to compare its selected columns. An ORDER BY cannot be used in a subquery, although the main query can use an ORDER BY. The GROUP BY can be used to perform the same function as the ORDER BY in a subquery. Subqueries that return more than one row can only be used with multiple value operators, such as the IN operator. The BETWEEN operator cannot be used with a subquery; however, the BETWEEN can be used within the subquery. Subqueries with the SELECT Statement: Subqueries are most frequently used with the SELECT statement. The basic syntax is as follows: SELECT column_name [, column_name ] FROM table1 [, table2 ] WHERE column_name OPERATOR (SELECT column_name [, column_name ] FROM table1 [, table2 ] [WHERE]) CHAPTER 39
- 116. TUTORIALS POINT Simply Easy Learning Example: Consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Now, let us check following sub-query with SELECT statement: sqlite> SELECT * FROM COMPANY WHERE ID IN (SELECT ID FROM COMPANY WHERE SALARY > 45000) ; This would produce the following result: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 Subqueries with the INSERT Statement: Subqueries also can be used with INSERT statements. The INSERT statement uses the data returned from the subquery to insert into another table. The selected data in the subquery can be modified with any of the character, date or number functions. The basic syntax is as follows: INSERT INTO table_name [ (column1 [, column2 ]) ] SELECT [ *|column1 [, column2 ] FROM table1 [, table2 ] [ WHERE VALUE OPERATOR ] Example: Consider a table COMPANY_BKP with similar structure as COMPANY table and can be created using same CREATE TABLE using COMPANY_BKP as table name. Now to copy complete COMPANY table into COMPANY_BKP, following is the syntax: sqlite> INSERT INTO COMPANY_BKP SELECT * FROM COMPANY WHERE ID IN (SELECT ID FROM COMPANY) ;
- 117. TUTORIALS POINT Simply Easy Learning Subqueries with the UPDATE Statement: The subquery can be used in conjunction with the UPDATE statement. Either single or multiple columns in a table can be updated when using a subquery with the UPDATE statement. The basic syntax is as follows: UPDATE table SET column_name = new_value [ WHERE OPERATOR [ VALUE ] (SELECT COLUMN_NAME FROM TABLE_NAME) [ WHERE) ] Example: Assuming, we have COMPANY_BKP table available which is backup of COMPANY table. Following example updates SALARY by 0.50 times in COMPANY table for all the customers, whose AGE is greater than or equal to 27: sqlite> UPDATE COMPANY SET SALARY = SALARY * 0.50 WHERE AGE IN (SELECT AGE FROM COMPANY_BKP WHERE AGE >= 27 ); This would impact two rows and finally COMPANY table would have the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 10000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 42500.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Subqueries with the DELETE Statement: The subquery can be used in conjunction with the DELETE statement like with any other statements mentioned above. The basic syntax is as follows: DELETE FROM TABLE_NAME [ WHERE OPERATOR [ VALUE ] (SELECT COLUMN_NAME FROM TABLE_NAME) [ WHERE) ] Example: Assuming, we have COMPANY_BKP table available which is backup of COMPANY table.
- 118. TUTORIALS POINT Simply Easy Learning Following example deletes records from COMPANY table for all the customers whose AGE is greater than or equal to 27: sqlite> DELETE FROM COMPANY WHERE AGE IN (SELECT AGE FROM COMPANY_BKP WHERE AGE > 27 ); This would impact two rows and finally COMPANY table would have the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 42500.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0
- 119. TUTORIALS POINT Simply Easy Learning SQLite AUTOINCREMENT SQLite AUTOINCREMENT is a keyword used for auto incrementing a value of a field in the table. We can auto increment a field value by using AUTOINCREMENT keyword when creating a table with specific column name to auto incrementing it. The keyword AUTOINCREMENT can be used with INTEGER field only. Syntax: The basic usage of AUTOINCREMENT keyword is as follows: CREATE TABLE table_name( column1 INTEGER AUTOINCREMENT, column2 datatype, column3 datatype, ..... columnN datatype, ); Example: Consider COMPANY table to be created as follows: sqlite> CREATE TABLE COMPANY( ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL ); Now, insert following records into table COMPANY: INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY) VALUES ( 'Paul', 32, 'California', 20000.00 ); INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY) VALUES ('Allen', 25, 'Texas', 15000.00 ); INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY) VALUES ('Teddy', 23, 'Norway', 20000.00 ); CHAPTER 40
- 120. TUTORIALS POINT Simply Easy Learning INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY) VALUES ( 'Mark', 25, 'Rich-Mond ', 65000.00 ); INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY) VALUES ( 'David', 27, 'Texas', 85000.00 ); INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY) VALUES ( 'Kim', 22, 'South-Hall', 45000.00 ); INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY) VALUES ( 'James', 24, 'Houston', 10000.00 ); This will insert 7 tuples into the table COMPANY and COMPANY will have the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0
- 121. TUTORIALS POINT Simply Easy Learning SQLite Injection If you take user input through a webpage and insert it into a SQLite database, there's a chance that you have left yourself wide open for a security issue known as SQL Injection. This lesson will teach you how to help prevent this from happening and help you secure your scripts and SQLite statements. Injection usually occurs when you ask a user for input, like their name, and instead of a name they give you a SQLite statement that you will unknowingly run on your database. Never trust user provided data, process this data only after validation; as a rule, this is done by pattern matching. In the example below, the username is restricted to alphanumerical chars plus underscore and to a length between 8 and 20 chars - modify these rules as needed. if (preg_match("/^w{8,20}$/", $_GET['username'], $matches)){ $db = new SQLiteDatabase('filename'); $result = @$db->query("SELECT * FROM users WHERE username=$matches[0]"); }else{ echo "username not accepted"; } To demonstrate the problem, consider this excerpt: $name = "Qadir'; DELETE FROM users;"; @$db->query("SELECT * FROM users WHERE username='{$name}'"); The function call is supposed to retrieve a record from the users table where the name column matches the name specified by the user. Under normal circumstances, $name would only contain alphanumeric characters and perhaps spaces, such as the string ilia. But here, by appending an entirely new query to $name, the call to the database turns into disaster: the injected DELETE query removes all records from users. There are database's interfaces which do not permit query stacking or executing multiple queries in a single function call. If you try to stack queries, the call fails but SQLite and PostgreSQL, happily perform stacked queries, executing all of the queries provided in one string and creating a serious security problem. Preventing SQL Injection: You can handle all escape characters smartly in scripting languages like PERL and PHP. Programming language PHP provides the function string sqlite_escape_string() to escape input characters that are special to SQLite. if (get_magic_quotes_gpc()) { $name = sqlite_escape_string($name); CHAPTER 41
- 122. TUTORIALS POINT Simply Easy Learning } $result = @$db->query("SELECT * FROM users WHERE username='{$name}'"); Although the encoding makes it safe to insert the data, it will render simple text comparisons and LIKEclauses in your queries unusable for the columns that contain the binary data. Keep a note that addslashes() should NOT be used to quote your strings for SQLite queries; it will lead to strange results when retrieving your data.
- 123. TUTORIALS POINT Simply Easy Learning SQLite Explain An SQLite statement can be preceded by the keyword "EXPLAIN" or by the phrase "EXPLAIN QUERY PLAN" used for describing the details of table. Either modification causes the SQLite statement to behave as a query and to return information about how the SQLite statement would have operated if the EXPLAIN keyword or phrase had been omitted. The output from EXPLAIN and EXPLAIN QUERY PLAN is intended for interactive analysis and troubleshooting only. The details of the output format are subject to change from one release of SQLite to the next. Applications should not use EXPLAIN or EXPLAIN QUERY PLAN since their exact behavior is variable and only partially documented. Syntax: Syntax for EXPLAIN is as follows: EXPLAIN [SQLite Query] Syntax for EXPLAIN QUERY PLAN is as follows: EXPLAIN QUERY PLAN [SQLite Query] Example: This is the file to create COMPANY table and to populate it with 7 records. -- Just copy and past them on sqlite> prompt. DROP TABLE COMPANY; CREATE TABLE COMPANY( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) CHAPTER 42
- 124. TUTORIALS POINT Simply Easy Learning VALUES (1, 'Paul', 32, 'California', 20000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (2, 'Allen', 25, 'Texas', 15000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (3, 'Teddy', 23, 'Norway', 20000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (5, 'David', 27, 'Texas', 85000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (6, 'Kim', 22, 'South-Hall', 45000.00 ); INSERT INTO COMPANY VALUES (7, 'James', 24, 'Houston', 10000.00 ); Consider above shown COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 Now, let us check following sub-query with SELECT statement: sqlite> EXPLAIN SELECT * FROM COMPANY WHERE Salary >= 20000; This would produce the following result: addr opcode p1 p2 p3 ---------- ---------- ---------- ---------- ---------- 0 Goto 0 19 1 Integer 0 0 2 OpenRead 0 8 3 SetNumColu 0 5 4 Rewind 0 17 5 Column 0 4 6 RealAffini 0 0 7 Integer 20000 0 8 Lt 357 16 collseq(BI 9 Rowid 0 0 10 Column 0 1 11 Column 0 2 12 Column 0 3 13 Column 0 4 14 RealAffini 0 0 15 Callback 5 0 16 Next 0 5 17 Close 0 0 18 Halt 0 0 19 Transactio 0 0
- 125. TUTORIALS POINT Simply Easy Learning 20 VerifyCook 0 38 21 Goto 0 1 22 Noop 0 0 Now, let us check following Explain Query Plan with SELECT statement: SQLite> EXPLAIN QUERY PLAN SELECT * FROM COMPANY WHERE Salary >= 20000; order from detail ---------- ---------- ------------- 0 0 TABLE COMPANY
- 126. TUTORIALS POINT Simply Easy Learning SQLite Vacuum The VACUUM command cleans the main database by copying its contents to a temporary database file and reloading the original database file from the copy. This eliminates free pages, aligns table data to be contiguous, and otherwise cleans up the database file structure. The VACUUM command may change the ROWID of entries in tables that do not have an explicit INTEGER PRIMARY KEY. The VACUUM command only works on the main database. It is not possible to VACUUM an attached database file. The VACUUM command will fail if there is an active transaction. The VACUUM command is a no-op for in- memory databases. As the VACUUM command rebuilds the database file from scratch, VACUUM can also be used to modify many database-specific configuration parameters. Manual VACUUM Following is simple syntax to issue a VACUUM command for the whole database from command prompt: $sqlite3 database_name "VACUUM;" You can run VACUUM from SQLite prompt as well as follows: sqlite> VACUUM; You can also run VACUUM on a particular table as follows: sqlite> VACUUM table_name; Auto-VACCUM SQLite Auto-VACUUM does not do the same as VACUUM rather it only moves free pages to the end of the database thereby reducing the database size. By doing so it can significantly fragment the database while VACUUM ensures defragmentation. So Auto-VACUUM just keeps the database small. You can enable/disable SQLite auto-vacuuming by the following pragmas running at SQLite prompt: sqlite> PRAGMA auto_vacuum = NONE; -- 0 means disable auto vacuum sqlite> PRAGMA auto_vacuum = INCREMENTAL; -- 1 means enable incremental vacuum sqlite> PRAGMA auto_vacuum = FULL; -- 2 means enable full auto vacuum CHAPTER 43
- 127. TUTORIALS POINT Simply Easy Learning You can run following command from command prompt to check the auto-vacuum setting: $sqlite3 database_name "PRAGMA auto_vacuum;"
- 128. TUTORIALS POINT Simply Easy Learning SQLite Date & Time SQLite supports five date and time functions as follows: S.N. Function Example 1 date(timestring, modifiers...) This returns the date in this format: YYYY-MM-DD 2 time(timestring, modifiers...) This returns the time as HH:MM:SS 3 datetime(timestring, modifiers...) This returns YYYY-MM-DD HH:MM:SS 4 julianday(timestring, modifiers...) This returns the number of days since noon in Greenwich on November 24, 4714 B.C. 5 strftime(timestring, modifiers...) This returns the date formatted according to the format string specified as the first argument formatted as per formatters explained below. All the above five date and time functions take a time string as an argument. The time string is followed by zero or more modifiers. The strftime() function also takes a format string as its first argument. Following section will give you detail on different types of time strings and modifiers. Time Strings: A time string can be in any of the following formats: S.N. Time String Example 1 YYYY-MM-DD 2010-12-30 2 YYYY-MM-DD HH:MM 2010-12-30 12:10 3 YYYY-MM-DD HH:MM:SS.SSS 2010-12-30 12:10:04.100 4 MM-DD-YYYY HH:MM 30-12-2010 12:10 5 HH:MM 12:10 6 YYYY-MM-DDTHH:MM 2010-12-30 12:10 7 HH:MM:SS 12:10:01 CHAPTER 44
- 129. TUTORIALS POINT Simply Easy Learning 8 YYYYMMDD HHMMSS 20101230 121001 9 Now 2013-05-07 You can use the "T" as a literal character separating the date and the time. Modifiers The time string can be followed by zero or more modifiers that will alter date and/or time returned by any of the above five functions. Modifiers are applied from left to right and following modifers are available in SQLite: NNN days NNN hours NNN minutes NNN.NNNN seconds NNN months NNN years start of month start of year start of day weekday N unixepoch localtime utc Formatters: SQLite provides very handy function strftime() to format any date and time. You can use following substitutions to format your date and time: Substitution Description %d Day of month, 01-31 %f Fractional seconds, SS.SSS %H Hour, 00-23 %j Day of year, 001-366 %J Julian day number, DDDD.DDDD
- 130. TUTORIALS POINT Simply Easy Learning %m Month, 00-12 %M Minute, 00-59 %s Seconds since 1970-01-01 %S Seconds, 00-59 %w Day of week, 0-6 (0 is Sunday) %W Week of year, 01-53 %Y Year, YYYY %% % symbol Examples Let's try various examples now using SQLite prompt. Following computes the current date: sqlite> SELECT date('now'); 2013-05-07 Following computes the last day of the current month: sqlite> SELECT date('now','start of month','+1 month','-1 day'); 2013-05-31 Following computes the date and time given a UNIX timestamp 1092941466: sqlite> SELECT datetime(1092941466, 'unixepoch'); 2004-08-19 18:51:06 Following computes the date and time given a UNIX timestamp 1092941466 and compensate for your local timezone: sqlite> SELECT datetime(1092941466, 'unixepoch', 'localtime'); 2004-08-19 11:51:06 Following computes the current UNIX timestamp: sqlite> SELECT datetime(1092941466, 'unixepoch', 'localtime'); 1367926057 Following computes the number of days since the signing of the US Declaration of Independence: sqlite> SELECT julianday('now') - julianday('1776-07-04'); 86504.4775830326 Following computes the number of seconds since a particular moment in 2004: sqlite> SELECT strftime('%s','now') - strftime('%s','2004-01-01 02:34:56'); 295001572 Following computes the date of the first Tuesday in October for the current year: sqlite> SELECT date('now','start of year','+9 months','weekday 2'); 2013-10-01
- 131. TUTORIALS POINT Simply Easy Learning Following computes the time since the UNIX epoch in seconds (like strftime('%s','now') except includes fractional part): sqlite> SELECT (julianday('now') - 2440587.5)*86400.0; 1367926077.12598 To convert between UTC and local time values when formatting a date, use the utc or localtime modifiers as follows: sqlite> SELECT time('12:00', 'localtime'); 05:00:00 sqlite> SELECT time('12:00', 'utc'); 19:00:00
- 132. TUTORIALS POINT Simply Easy Learning SQLite Useful Functions SQLite has many built-in functions for performing processing on string or numeric data. Following is the list of few useful SQLite built-in functions and all are case insensitive, which means you can use these functions either in lower-case form or in upper-case or in mixed form. For more details, you can check official documentation for SQLite: S.N. Function & Description 1 SQLite COUNT Function The SQLite COUNT aggregate function is used to count the number of rows in a database table. 2 SQLite MAX Function The SQLite MAX aggregate function allows us to select the highest (maximum) value for a certain column. 3 SQLite MIN Function The SQLite MIN aggregate function allows us to select the lowest (minimum) value for a certain column. 4 SQLite AVG Function The SQLite AVG aggregate function selects the average value for certain table column. 5 SQLite SUM Function The SQLite SUM aggregate function allows selecting the total for a numeric column. 6 SQLite RANDOM Function The SQLite RANDOM function returns a pseudo-random integer between -9223372036854775808 and +9223372036854775807. 7 SQLite ABS Function The SQLite ABS function returns the absolute value of the numeric argument. 8 SQLite UPPER Function The SQLite UPPER function converts a string into upper-case letters. 9 SQLite LOWER Function The SQLite LOWER function converts a string into lower-case letters. 10 SQLite LENGTH Function The SQLite LENGTH function returns the length of a string. 11 SQLite sqlite_version Function The SQLite sqlite_version function returns the version of the SQLite library. CHAPTER 45
- 133. TUTORIALS POINT Simply Easy Learning Before we start giving examples on the above mentioned functions, consider COMPANY table is having the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 SQLite COUNT Function The SQLite COUNT aggregate function is used to count the number of rows in a database table. Following is the example: sqlite> SELECT count(*) FROM COMPANY; Above SQLite SQL statement will produce the following result: count(*) ---------- 7 SQLite MAX Function The SQLite MAX aggregate function allows us to select the highest (maximum) value for a certain column. Following is the example: sqlite> SELECT max(salary) FROM COMPANY; Above SQLite SQL statement will produce the following result: max(salary) ----------- 85000.0 SQLite MIN Function The SQLite MIN aggregate function allows us to select the lowest (minimum) value for a certain column. Following is the example: sqlite> SELECT min(salary) FROM COMPANY; Above SQLite SQL statement will produce the following result: min(salary) ----------- 10000.0 SQLite AVG Function The SQLite AVG aggregate function selects the average value for certain table column. Following is the example:
- 134. TUTORIALS POINT Simply Easy Learning sqlite> SELECT avg(salary) FROM COMPANY; Above SQLite SQL statement will produce the following result: avg(salary) ---------------- 37142.8571428572 SQLite SUM Function The SQLite SUM aggregate function allows selecting the total for a numeric column. Following is the example: sqlite> SELECT sum(salary) FROM COMPANY; Above SQLite SQL statement will produce the following result: sum(salary) ----------- 260000.0 SQLite RANDOM Function The SQLite RANDOM function returns a pseudo-random integer between -9223372036854775808 and +9223372036854775807. Following is the example: sqlite> SELECT random() AS Random; Above SQLite SQL statement will produce the following result: Random ------------------- 5876796417670984050 SQLite ABS Function The SQLite ABS function returns the absolute value of the numeric argument. Following is the example: sqlite> SELECT abs(5), abs(-15), abs(NULL), abs(0), abs("ABC"); Above SQLite SQL statement will produce following result: abs(5) abs(-15) abs(NULL) abs(0) abs("ABC") ---------- ---------- ---------- ---------- ---------- 5 15 0 0.0 SQLite UPPER Function The SQLite UPPER function converts a string into upper-case letters. Following is the example: sqlite> SELECT upper(name) FROM COMPANY; Above SQLite SQL statement will produce the following result: upper(name)
- 135. TUTORIALS POINT Simply Easy Learning ----------- PAUL ALLEN TEDDY MARK DAVID KIM JAMES SQLite LOWER Function The SQLite LOWER function converts a string into lower-case letters. Following is the example: sqlite> SELECT lower(name) FROM COMPANY; Above SQLite SQL statement will produce the following result: lower(name) ----------- paul allen teddy mark david kim james SQLite LENGTH Function The SQLite LENGTH function returns the length of a string. Following is the example: sqlite> SELECT name, length(name) FROM COMPANY; Above SQLite SQL statement will produce the following result: NAME length(name) ---------- ------------ Paul 4 Allen 5 Teddy 5 Mark 4 David 5 Kim 3 James 5 SQLite sqlite_version Function The SQLite sqlite_version function returns the version of the SQLite library. Following is the example: sqlite> SELECT sqlite_version() AS 'SQLite Version'; Above SQLite SQL statement will produce the following result: SQLite Version -------------- 3.6.20
- 136. TUTORIALS POINT Simply Easy Learning SQLite C/C++ Tutorial Installation Before we start using SQLite in our C/C++ programs, we need to make sure that we have SQLite library set up on the machine. You can check SQLite Installation chapter to understand installation process. C/C++ Interface APIs Following are important SQLite routines, which can suffice your requirement to work with SQLite database from your C/C++ program. If you are looking for a more sophisticated application, then you can look into SQLite official documentation. S.N. API & Description 1 sqlite3_open(const char *filename, sqlite3 **ppDb) This routine opens a connection to an SQLite database file and returns a database connection object to be used by other SQLite routines. If the filename argument is NULL or ':memory:', sqlite3_open() will create an in-memory database in RAM that lasts only for the duration of the session. If filename is not NULL, sqlite3_open() attempts to open the database file by using its value. If no file by that name exists, sqlite3_open() will open a new database file by that name. 2 sqlite3_exec(sqlite3*, const char *sql, sqlite_callback, void *data, char **errmsg) This routine provides a quick, easy way to execute SQL commands provided by sql argument which can consist of more than one SQL command. Here, first argument sqlite3 is open database object, sqlite_callback is a call back for whichdata is the 1st argument and errmsg will be return to capture any error raised by the routine. The sqlite3_exec() routine parses and executes every command given in the sql argument until it reaches the end of the string or encounters an error. 3 sqlite3_close(sqlite3*) This routine closes a database connection previously opened by a call to sqlite3_open(). All prepared CHAPTER 46
- 137. TUTORIALS POINT Simply Easy Learning statements associated with the connection should be finalized prior to closing the connection. If any queries remain that have not been finalized, sqlite3_close() will return SQLITE_BUSY with the error message Unable to close due to unfinalized statements. Connecting To Database Following C code segment shows how to connect to an existing database. If database does not exist, then it will be created and finally a database object will be returned. #include <stdio.h> #include <sqlite3.h> int main(int argc, char* argv[]) { sqlite3 *db; char *zErrMsg = 0; int rc; rc = sqlite3_open("test.db", &db); if( rc ){ fprintf(stderr, "Can't open database: %sn", sqlite3_errmsg(db)); exit(0); }else{ fprintf(stderr, "Opened database successfullyn"); } sqlite3_close(db); } Now, let's compile and run above program to create our database test.db in the current directory. You can change your path as per your requirement. $gcc test.c -l sqlite3 $./a.out Opened database successfully If you are going to use C++ source code, then you can compile your code as follows: $g++ test.c -l sqlite3 Here, we are linking our program with sqlite3 library to provide required functions to C program. This will create a database file test.db in your directory and you will have the result something as follows: -rwxr-xr-x. 1 root root 7383 May 8 02:06 a.out -rw-r--r--. 1 root root 323 May 8 02:05 test.c -rw-r--r--. 1 root root 0 May 8 02:06 test.db Create a Table Following C code segment will be used to create a table in previously created database: #include <stdio.h> #include <stdlib.h> #include <sqlite3.h> static int callback(void *NotUsed, int argc, char **argv, char **azColName){
- 138. TUTORIALS POINT Simply Easy Learning int i; for(i=0; i<argc; i++){ printf("%s = %sn", azColName[i], argv[i] ? argv[i] : "NULL"); } printf("n"); return 0; } int main(int argc, char* argv[]) { sqlite3 *db; char *zErrMsg = 0; int rc; char *sql; /* Open database */ rc = sqlite3_open("test.db", &db); if( rc ){ fprintf(stderr, "Can't open database: %sn", sqlite3_errmsg(db)); exit(0); }else{ fprintf(stdout, "Opened database successfullyn"); } /* Create SQL statement */ sql = "CREATE TABLE COMPANY(" "ID INT PRIMARY KEY NOT NULL," "NAME TEXT NOT NULL," "AGE INT NOT NULL," "ADDRESS CHAR(50)," "SALARY REAL );"; /* Execute SQL statement */ rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg); if( rc != SQLITE_OK ){ fprintf(stderr, "SQL error: %sn", zErrMsg); sqlite3_free(zErrMsg); }else{ fprintf(stdout, "Table created successfullyn"); } sqlite3_close(db); return 0; } When above program is compiled and executed, it will create COMPANY table in your test.db and final listing of the file will be as follows: -rwxr-xr-x. 1 root root 9567 May 8 02:31 a.out -rw-r--r--. 1 root root 1207 May 8 02:31 test.c -rw-r--r--. 1 root root 3072 May 8 02:31 test.db INSERT Operation Following C code segment shows how we can create records in our COMPANY table created in above example: #include <stdio.h> #include <stdlib.h> #include <sqlite3.h>
- 139. TUTORIALS POINT Simply Easy Learning static int callback(void *NotUsed, int argc, char **argv, char **azColName){ int i; for(i=0; i<argc; i++){ printf("%s = %sn", azColName[i], argv[i] ? argv[i] : "NULL"); } printf("n"); return 0; } int main(int argc, char* argv[]) { sqlite3 *db; char *zErrMsg = 0; int rc; char *sql; /* Open database */ rc = sqlite3_open("test.db", &db); if( rc ){ fprintf(stderr, "Can't open database: %sn", sqlite3_errmsg(db)); exit(0); }else{ fprintf(stderr, "Opened database successfullyn"); } /* Create SQL statement */ sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " "VALUES (1, 'Paul', 32, 'California', 20000.00 ); " "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " "VALUES (2, 'Allen', 25, 'Texas', 15000.00 ); " "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)" "VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );" "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)" "VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 );"; /* Execute SQL statement */ rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg); if( rc != SQLITE_OK ){ fprintf(stderr, "SQL error: %sn", zErrMsg); sqlite3_free(zErrMsg); }else{ fprintf(stdout, "Records created successfullyn"); } sqlite3_close(db); return 0; } When above program is compiled and executed, it will create given records in COMPANY table and will display following two line: Opened database successfully Records created successfully SELECT Operation Before we proceed with actual example to fetch records, let me give a little detail about the callback function, which we are using in our examples. This callback provides a way to obtain results from SELECT statements. It has the following declaration: typedef int (*sqlite3_callback)(
- 140. TUTORIALS POINT Simply Easy Learning void*, /* Data provided in the 4th argument of sqlite3_exec() */ int, /* The number of columns in row */ char**, /* An array of strings representing fields in the row */ char** /* An array of strings representing column names */ ); If above callback is provided in sqlite_exec() routine as the third argument, SQLite will call the this callback function for each record processed in each SELECT statement executed within the SQL argument. Following C code segment shows how we can fetch and display records from our COMPANY table created in above example: #include <stdio.h> #include <stdlib.h> #include <sqlite3.h> static int callback(void *data, int argc, char **argv, char **azColName){ int i; fprintf(stderr, "%s: ", (const char*)data); for(i=0; i<argc; i++){ printf("%s = %sn", azColName[i], argv[i] ? argv[i] : "NULL"); } printf("n"); return 0; } int main(int argc, char* argv[]) { sqlite3 *db; char *zErrMsg = 0; int rc; char *sql; const char* data = "Callback function called"; /* Open database */ rc = sqlite3_open("test.db", &db); if( rc ){ fprintf(stderr, "Can't open database: %sn", sqlite3_errmsg(db)); exit(0); }else{ fprintf(stderr, "Opened database successfullyn"); } /* Create SQL statement */ sql = "SELECT * from COMPANY"; /* Execute SQL statement */ rc = sqlite3_exec(db, sql, callback, (void*)data, &zErrMsg); if( rc != SQLITE_OK ){ fprintf(stderr, "SQL error: %sn", zErrMsg); sqlite3_free(zErrMsg); }else{ fprintf(stdout, "Operation done successfullyn"); } sqlite3_close(db); return 0; } When above program is compiled and executed, it will produce the following result:
- 141. TUTORIALS POINT Simply Easy Learning Opened database successfully Callback function called: ID = 1 NAME = Paul AGE = 32 ADDRESS = California SALARY = 20000.0 Callback function called: ID = 2 NAME = Allen AGE = 25 ADDRESS = Texas SALARY = 15000.0 Callback function called: ID = 3 NAME = Teddy AGE = 23 ADDRESS = Norway SALARY = 20000.0 Callback function called: ID = 4 NAME = Mark AGE = 25 ADDRESS = Rich-Mond SALARY = 65000.0 Operation done successfully UPDATE Operation Following C code segment shows how we can use UPDATE statement to update any record and then fetch and display updated records from our COMPANY table: #include <stdio.h> #include <stdlib.h> #include <sqlite3.h> static int callback(void *data, int argc, char **argv, char **azColName){ int i; fprintf(stderr, "%s: ", (const char*)data); for(i=0; i<argc; i++){ printf("%s = %sn", azColName[i], argv[i] ? argv[i] : "NULL"); } printf("n"); return 0; } int main(int argc, char* argv[]) { sqlite3 *db; char *zErrMsg = 0; int rc; char *sql; const char* data = "Callback function called"; /* Open database */ rc = sqlite3_open("test.db", &db); if( rc ){ fprintf(stderr, "Can't open database: %sn", sqlite3_errmsg(db)); exit(0); }else{
- 142. TUTORIALS POINT Simply Easy Learning fprintf(stderr, "Opened database successfullyn"); } /* Create merged SQL statement */ sql = "UPDATE COMPANY set SALARY = 25000.00 where ID=1; " "SELECT * from COMPANY"; /* Execute SQL statement */ rc = sqlite3_exec(db, sql, callback, (void*)data, &zErrMsg); if( rc != SQLITE_OK ){ fprintf(stderr, "SQL error: %sn", zErrMsg); sqlite3_free(zErrMsg); }else{ fprintf(stdout, "Operation done successfullyn"); } sqlite3_close(db); return 0; } When above program is compiled and executed, it will produce the following result: Opened database successfully Callback function called: ID = 1 NAME = Paul AGE = 32 ADDRESS = California SALARY = 25000.0 Callback function called: ID = 2 NAME = Allen AGE = 25 ADDRESS = Texas SALARY = 15000.0 Callback function called: ID = 3 NAME = Teddy AGE = 23 ADDRESS = Norway SALARY = 20000.0 Callback function called: ID = 4 NAME = Mark AGE = 25 ADDRESS = Rich-Mond SALARY = 65000.0 Operation done successfully DELETE Operation Following C code segment shows how we can use DELETE statement to delete any record and then fetch and display remaining records from our COMPANY table: #include <stdio.h> #include <stdlib.h> #include <sqlite3.h> static int callback(void *data, int argc, char **argv, char **azColName){ int i; fprintf(stderr, "%s: ", (const char*)data);
- 143. TUTORIALS POINT Simply Easy Learning for(i=0; i<argc; i++){ printf("%s = %sn", azColName[i], argv[i] ? argv[i] : "NULL"); } printf("n"); return 0; } int main(int argc, char* argv[]) { sqlite3 *db; char *zErrMsg = 0; int rc; char *sql; const char* data = "Callback function called"; /* Open database */ rc = sqlite3_open("test.db", &db); if( rc ){ fprintf(stderr, "Can't open database: %sn", sqlite3_errmsg(db)); exit(0); }else{ fprintf(stderr, "Opened database successfullyn"); } /* Create merged SQL statement */ sql = "DELETE from COMPANY where ID=2; " "SELECT * from COMPANY"; /* Execute SQL statement */ rc = sqlite3_exec(db, sql, callback, (void*)data, &zErrMsg); if( rc != SQLITE_OK ){ fprintf(stderr, "SQL error: %sn", zErrMsg); sqlite3_free(zErrMsg); }else{ fprintf(stdout, "Operation done successfullyn"); } sqlite3_close(db); return 0; } When above program is compiled and executed, it will produce the following result: Opened database successfully Callback function called: ID = 1 NAME = Paul AGE = 32 ADDRESS = California SALARY = 20000.0 Callback function called: ID = 3 NAME = Teddy AGE = 23 ADDRESS = Norway SALARY = 20000.0 Callback function called: ID = 4 NAME = Mark AGE = 25 ADDRESS = Rich-Mond SALARY = 65000.0
- 144. TUTORIALS POINT Simply Easy Learning Operation done successfully
- 145. TUTORIALS POINT Simply Easy Learning SQLite Java Tutorial Installation Before we start using SQLite in our Java programs, we need to make sure that we have SQLite JDBC Driver and Java set up on the machine. You can check Java tutorial for Java installation on your machine. Now, let us check how to set up SQLite JDBC driver. Download latest version of sqlite-jdbc-(VERSION).jar from sqlite-jdbc repository. Add downloaded jar file sqlite-jdbc-(VERSION).jar in your class path, or you can use it along with -classpath option as explained below in examples. Following section assumes you have little knowledge about Java JDBC concepts. If you don't, then it is suggested to spent half an hour with JDBC Tutorial to become comfortable with concepts explained below. Connecting To Database Following Java programs shows how to connect to an existing database. If database does not exist, then it will be created and finally a database object will be returned. import java.sql.*; public class SQLiteJDBC { public static void main( String args[] ) { Connection c = null; try { Class.forName("org.sqlite.JDBC"); c = DriverManager.getConnection("jdbc:sqlite:test.db"); } catch ( Exception e ) { System.err.println( e.getClass().getName() + ": " + e.getMessage() ); System.exit(0); } System.out.println("Opened database successfully"); } } Now, let's compile and run above program to create our database test.db in the current directory. You can change your path as per your requirement. We are assuming current version of JDBC driver sqlite-jdbc-3.7.2.jar is available in the current path CHAPTER 47
- 146. TUTORIALS POINT Simply Easy Learning $javac SQLiteJDBC.java $java -classpath ".:sqlite-jdbc-3.7.2.jar" SQLiteJDBC Open database successfully If you are going to use Windows machine, then you can compile and run your code as follows: $javac SQLiteJDBC.java $java -classpath ".;sqlite-jdbc-3.7.2.jar" SQLiteJDBC Opened database successfully Create a Table Following Java program will be used to create a table in previously created database: import java.sql.*; public class SQLiteJDBC { public static void main( String args[] ) { Connection c = null; Statement stmt = null; try { Class.forName("org.sqlite.JDBC"); c = DriverManager.getConnection("jdbc:sqlite:test.db"); System.out.println("Opened database successfully"); stmt = c.createStatement(); String sql = "CREATE TABLE COMPANY " + "(ID INT PRIMARY KEY NOT NULL," + " NAME TEXT NOT NULL, " + " AGE INT NOT NULL, " + " ADDRESS CHAR(50), " + " SALARY REAL)"; stmt.executeUpdate(sql); stmt.close(); c.close(); } catch ( Exception e ) { System.err.println( e.getClass().getName() + ": " + e.getMessage() ); System.exit(0); } System.out.println("Table created successfully"); } } When above program is compiled and executed, it will create COMPANY table in your test.db and final listing of the file will be as follows: -rw-r--r--. 1 root root 3201128 Jan 22 19:04 sqlite-jdbc-3.7.2.jar -rw-r--r--. 1 root root 1506 May 8 05:43 SQLiteJDBC.class -rw-r--r--. 1 root root 832 May 8 05:42 SQLiteJDBC.java -rw-r--r--. 1 root root 3072 May 8 05:43 test.db INSERT Operation Following Java program shows how we can create records in our COMPANY table created in above example: import java.sql.*;
- 147. TUTORIALS POINT Simply Easy Learning public class SQLiteJDBC { public static void main( String args[] ) { Connection c = null; Statement stmt = null; try { Class.forName("org.sqlite.JDBC"); c = DriverManager.getConnection("jdbc:sqlite:test.db"); c.setAutoCommit(false); System.out.println("Opened database successfully"); stmt = c.createStatement(); String sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " + "VALUES (1, 'Paul', 32, 'California', 20000.00 );"; stmt.executeUpdate(sql); sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " + "VALUES (2, 'Allen', 25, 'Texas', 15000.00 );"; stmt.executeUpdate(sql); sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " + "VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );"; stmt.executeUpdate(sql); sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " + "VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 );"; stmt.executeUpdate(sql); stmt.close(); c.commit(); c.close(); } catch ( Exception e ) { System.err.println( e.getClass().getName() + ": " + e.getMessage() ); System.exit(0); } System.out.println("Records created successfully"); } } When above program is compiled and executed, it will create given records in COMPANY table and will display following two line: Opened database successfully Records created successfully SELECT Operation Following Java program shows how we can fetch and display records from our COMPANY table created in above example: import java.sql.*; public class SQLiteJDBC { public static void main( String args[] ) { Connection c = null; Statement stmt = null;
- 148. TUTORIALS POINT Simply Easy Learning try { Class.forName("org.sqlite.JDBC"); c = DriverManager.getConnection("jdbc:sqlite:test.db"); c.setAutoCommit(false); System.out.println("Opened database successfully"); stmt = c.createStatement(); ResultSet rs = stmt.executeQuery( "SELECT * FROM COMPANY;" ); while ( rs.next() ) { int id = rs.getInt("id"); String name = rs.getString("name"); int age = rs.getInt("age"); String address = rs.getString("address"); float salary = rs.getFloat("salary"); System.out.println( "ID = " + id ); System.out.println( "NAME = " + name ); System.out.println( "AGE = " + age ); System.out.println( "ADDRESS = " + address ); System.out.println( "SALARY = " + salary ); System.out.println(); } rs.close(); stmt.close(); c.close(); } catch ( Exception e ) { System.err.println( e.getClass().getName() + ": " + e.getMessage() ); System.exit(0); } System.out.println("Operation done successfully"); } } When above program is compiled and executed, it will produce the following result: Opened database successfully ID = 1 NAME = Paul AGE = 32 ADDRESS = California SALARY = 20000.0 ID = 2 NAME = Allen AGE = 25 ADDRESS = Texas SALARY = 15000.0 ID = 3 NAME = Teddy AGE = 23 ADDRESS = Norway SALARY = 20000.0 ID = 4 NAME = Mark AGE = 25 ADDRESS = Rich-Mond SALARY = 65000.0 Operation done successfully
- 149. TUTORIALS POINT Simply Easy Learning UPDATE Operation Following Java code shows how we can use UPDATE statement to update any record and then fetch and display updated records from our COMPANY table: import java.sql.*; public class SQLiteJDBC { public static void main( String args[] ) { Connection c = null; Statement stmt = null; try { Class.forName("org.sqlite.JDBC"); c = DriverManager.getConnection("jdbc:sqlite:test.db"); c.setAutoCommit(false); System.out.println("Opened database successfully"); stmt = c.createStatement(); String sql = "UPDATE COMPANY set SALARY = 25000.00 where ID=1;"; stmt.executeUpdate(sql); c.commit(); ResultSet rs = stmt.executeQuery( "SELECT * FROM COMPANY;" ); while ( rs.next() ) { int id = rs.getInt("id"); String name = rs.getString("name"); int age = rs.getInt("age"); String address = rs.getString("address"); float salary = rs.getFloat("salary"); System.out.println( "ID = " + id ); System.out.println( "NAME = " + name ); System.out.println( "AGE = " + age ); System.out.println( "ADDRESS = " + address ); System.out.println( "SALARY = " + salary ); System.out.println(); } rs.close(); stmt.close(); c.close(); } catch ( Exception e ) { System.err.println( e.getClass().getName() + ": " + e.getMessage() ); System.exit(0); } System.out.println("Operation done successfully"); } } When above program is compiled and executed, it will produce the following result: Opened database successfully ID = 1 NAME = Paul AGE = 32 ADDRESS = California SALARY = 25000.0 ID = 2 NAME = Allen
- 150. TUTORIALS POINT Simply Easy Learning AGE = 25 ADDRESS = Texas SALARY = 15000.0 ID = 3 NAME = Teddy AGE = 23 ADDRESS = Norway SALARY = 20000.0 ID = 4 NAME = Mark AGE = 25 ADDRESS = Rich-Mond SALARY = 65000.0 Operation done successfully DELETE Operation Following Java code shows how we can use DELETE statement to delete any record and then fetch and display remaining records from our COMPANY table: import java.sql.*; public class SQLiteJDBC { public static void main( String args[] ) { Connection c = null; Statement stmt = null; try { Class.forName("org.sqlite.JDBC"); c = DriverManager.getConnection("jdbc:sqlite:test.db"); c.setAutoCommit(false); System.out.println("Opened database successfully"); stmt = c.createStatement(); String sql = "DELETE from COMPANY where ID=2;"; stmt.executeUpdate(sql); c.commit(); ResultSet rs = stmt.executeQuery( "SELECT * FROM COMPANY;" ); while ( rs.next() ) { int id = rs.getInt("id"); String name = rs.getString("name"); int age = rs.getInt("age"); String address = rs.getString("address"); float salary = rs.getFloat("salary"); System.out.println( "ID = " + id ); System.out.println( "NAME = " + name ); System.out.println( "AGE = " + age ); System.out.println( "ADDRESS = " + address ); System.out.println( "SALARY = " + salary ); System.out.println(); } rs.close(); stmt.close(); c.close(); } catch ( Exception e ) {
- 151. TUTORIALS POINT Simply Easy Learning System.err.println( e.getClass().getName() + ": " + e.getMessage() ); System.exit(0); } System.out.println("Operation done successfully"); } } When above program is compiled and executed, it will produce the following result: Opened database successfully ID = 1 NAME = Paul AGE = 32 ADDRESS = California SALARY = 25000.0 ID = 3 NAME = Teddy AGE = 23 ADDRESS = Norway SALARY = 20000.0 ID = 4 NAME = Mark AGE = 25 ADDRESS = Rich-Mond SALARY = 65000.0 Operation done successfully
- 152. TUTORIALS POINT Simply Easy Learning SQLite PHP Tutorial Installation The SQLite3 extension is enabled by default as of PHP 5.3.0. It's possible to disable it by using --without- sqlite3 at compile time. Windows users must enable php_sqlite3.dll in order to use this extension. This DLL is included with Windows distributions of PHP as of PHP 5.3.0. For detailed installation instructions, kindly check our PHP tutorial and its official website. PHP Interface APIs Following are important PHP routines, which can suffice your requirement to work with SQLite database from your PHP program. If you are looking for a more sophisticated application, then you can look into PHP official documentation. S.N. API & Description 1 public void SQLite3::open ( filename, flags, encryption_key ) Opens an SQLite 3 Database. If the build includes encryption, then it will attempt to use the key. If the filename is given as ':memory:', SQLite3::open() will create an in-memory database in RAM that lasts only for the duration of the session. If filename is actual device file name, SQLite3::open() attempts to open the database file by using its value. If no file by that name exists then a new database file by that name gets created. Optional flags used to determine how to open the SQLite database. By default, open uses SQLITE3_OPEN_READWRITE | SQLITE3_OPEN_CREATE. 2 public bool SQLite3::exec ( string $query ) This routine provides a quick, easy way to execute SQL commands provided by sql argument which can consist of more than one SQL command. This routine is used to execute a result-less query against a given database. CHAPTER 48
- 153. TUTORIALS POINT Simply Easy Learning 3 public SQLite3Result SQLite3::query ( string $query ) This routine executes an SQL query, returning an SQLite3Result object if the query returns results. 4 public int SQLite3::lastErrorCode ( void ) This routine returns the numeric result code of the most recent failed SQLite request 5 public string SQLite3::lastErrorMsg ( void ) This routine returns english text describing the most recent failed SQLite request. 6 public int SQLite3::changes ( void ) This routine returns the number of database rows that were updated or inserted or deleted by the most recent SQL statement 7 public bool SQLite3::close ( void ) This routine closes a database connection previously opened by a call to SQLite3::open(). 8 public string SQLite3::escapeString ( string $value ) This routine returns a string that has been properly escaped for safe inclusion in an SQL statement. Connecting To Database Following PHP code shows how to connect to an existing database. If database does not exist, then it will be created and finally a database object will be returned. <?php class MyDB extends SQLite3 { function __construct() { $this->open('test.db'); } } $db = new MyDB(); if(!$db){ echo $db->lastErrorMsg(); } else { echo "Opened database successfullyn"; } ?> Now, let's run above program to create our database test.db in the current directory. You can change your path as per your requirement. If database is successfully created, then it will give the following message: Open database successfully Create a Table Following PHP program will be used to create a table in previously created database:
- 154. TUTORIALS POINT Simply Easy Learning <?php class MyDB extends SQLite3 { function __construct() { $this->open('test.db'); } } $db = new MyDB(); if(!$db){ echo $db->lastErrorMsg(); } else { echo "Opened database successfullyn"; } $sql =<<<EOF CREATE TABLE COMPANY (ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL); EOF; $ret = $db->exec($sql); if(!$ret){ echo $db->lastErrorMsg(); } else { echo "Table created successfullyn"; } $db->close(); ?> When above program is executed, it will create COMPANY table in your test.db and it will display the following messages: Opened database successfully Table created successfully INSERT Operation Following PHP program shows how we can create records in our COMPANY table created in above example: <?php class MyDB extends SQLite3 { function __construct() { $this->open('test.db'); } } $db = new MyDB(); if(!$db){ echo $db->lastErrorMsg(); } else { echo "Opened database successfullyn"; } $sql =<<<EOF
- 155. TUTORIALS POINT Simply Easy Learning INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (1, 'Paul', 32, 'California', 20000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (2, 'Allen', 25, 'Texas', 15000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (3, 'Teddy', 23, 'Norway', 20000.00 ); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 ); EOF; $ret = $db->exec($sql); if(!$ret){ echo $db->lastErrorMsg(); } else { echo "Records created successfullyn"; } $db->close(); ?> When above program is executed, it will create given records in COMPANY table and will display the following two lines: Opened database successfully Records created successfully SELECT Operation Following PHP program shows how we can fetch and display records from our COMPANY table created in above example: <?php class MyDB extends SQLite3 { function __construct() { $this->open('test.db'); } } $db = new MyDB(); if(!$db){ echo $db->lastErrorMsg(); } else { echo "Opened database successfullyn"; } $sql =<<<EOF SELECT * from COMPANY; EOF; $ret = $db->query($sql); while($row = $ret->fetchArray(SQLITE3_ASSOC) ){ echo "ID = ". $row['ID'] . "n"; echo "NAME = ". $row['NAME'] ."n"; echo "ADDRESS = ". $row['ADDRESS'] ."n"; echo "SALARY = ".$row['SALARY'] ."nn"; } echo "Operation done successfullyn";
- 156. TUTORIALS POINT Simply Easy Learning $db->close(); ?> When above program is executed, it will produce the following result: Opened database successfully ID = 1 NAME = Paul ADDRESS = California SALARY = 20000 ID = 2 NAME = Allen ADDRESS = Texas SALARY = 15000 ID = 3 NAME = Teddy ADDRESS = Norway SALARY = 20000 ID = 4 NAME = Mark ADDRESS = Rich-Mond SALARY = 65000 Operation done successfully UPDATE Operation Following PHP code shows how we can use UPDATE statement to update any record and then fetch and display updated records from our COMPANY table: <?php class MyDB extends SQLite3 { function __construct() { $this->open('test.db'); } } $db = new MyDB(); if(!$db){ echo $db->lastErrorMsg(); } else { echo "Opened database successfullyn"; } $sql =<<<EOF UPDATE COMPANY set SALARY = 25000.00 where ID=1; EOF; $ret = $db->exec($sql); if(!$ret){ echo $db->lastErrorMsg(); } else { echo $db->changes(), " Record updated successfullyn"; } $sql =<<<EOF SELECT * from COMPANY; EOF;
- 157. TUTORIALS POINT Simply Easy Learning $ret = $db->query($sql); while($row = $ret->fetchArray(SQLITE3_ASSOC) ){ echo "ID = ". $row['ID'] . "n"; echo "NAME = ". $row['NAME'] ."n"; echo "ADDRESS = ". $row['ADDRESS'] ."n"; echo "SALARY = ".$row['SALARY'] ."nn"; } echo "Operation done successfullyn"; $db->close(); ?> When above program is executed, it will produce the following result: Opened database successfully 1 Record updated successfully ID = 1 NAME = Paul ADDRESS = California SALARY = 25000 ID = 2 NAME = Allen ADDRESS = Texas SALARY = 15000 ID = 3 NAME = Teddy ADDRESS = Norway SALARY = 20000 ID = 4 NAME = Mark ADDRESS = Rich-Mond SALARY = 65000 Operation done successfully DELETE Operation Following PHP code shows how we can use DELETE statement to delete any record and then fetch and display remaining records from our COMPANY table: <?php class MyDB extends SQLite3 { function __construct() { $this->open('test.db'); } } $db = new MyDB(); if(!$db){ echo $db->lastErrorMsg(); } else { echo "Opened database successfullyn"; } $sql =<<<EOF DELETE from COMPANY where ID=2; EOF; $ret = $db->exec($sql);
- 158. TUTORIALS POINT Simply Easy Learning if(!$ret){ echo $db->lastErrorMsg(); } else { echo $db->changes(), " Record deleted successfullyn"; } $sql =<<<EOF SELECT * from COMPANY; EOF; $ret = $db->query($sql); while($row = $ret->fetchArray(SQLITE3_ASSOC) ){ echo "ID = ". $row['ID'] . "n"; echo "NAME = ". $row['NAME'] ."n"; echo "ADDRESS = ". $row['ADDRESS'] ."n"; echo "SALARY = ".$row['SALARY'] ."nn"; } echo "Operation done successfullyn"; $db->close(); ?> When above program is executed, it will produce the following result: Opened database successfully 1 Record deleted successfully ID = 1 NAME = Paul ADDRESS = California SALARY = 25000 ID = 3 NAME = Teddy ADDRESS = Norway SALARY = 20000 ID = 4 NAME = Mark ADDRESS = Rich-Mond SALARY = 65000 Operation done successfully
- 159. TUTORIALS POINT Simply Easy Learning SQLite Perl Tutorial Installation The SQLite3 can be integrated with Perl using Perl DBI module, which is a database access module for the Perl programming language. It defines a set of methods, variables and conventions that provide a standard database interface. Here are simple steps to install DBI module on your Linux/UNIX machine: $ wget http://search.cpan.org/CPAN/authors/id/T/TI/TIMB/DBI-1.625.tar.gz $ tar xvfz DBI-1.625.tar.gz $ cd DBI-1.625 $ perl Makefile.PL $ make $ make install If you need to install SQLite driver for DBI, then it can be installed as follows: $ wget http://search.cpan.org/CPAN/authors/id/M/MS/MSERGEANT/DBD-SQLite-1.11.tar.gz $ tar xvfz DBD-SQLite-1.11.tar.gz $ cd DBD-SQLite-1.11 $ perl Makefile.PL $ make $ make install DBI Interface APIs Following are important DBI routines, which can suffice your requirement to work with SQLite database from your Perl program. If you are looking for a more sophisticated application, then you can look into Perl DBI official documentation. S.N. API & Description 1 DBI->connect($data_source, "", "", %attr) Establishes a database connection, or session, to the requested $data_source. Returns a database handle object if the connection succeeds. Datasource has the form like : DBI:SQLite:dbname='test.db' SQLite is SQLite driver name and CHAPTER 49
- 160. TUTORIALS POINT Simply Easy Learning test.db is the name of SQLite database file. If the filename is given as ':memory:', it will create an in-memory database in RAM that lasts only for the duration of the session. If filename is actual device file name, then it attempts to open the database file by using its value. If no file by that name exists then a new database file by that name gets created. You keep second and third paramter as blank strings and last parameter is to pass various attributes as shown below in the example. 2 $dbh->do($sql) This routine prepares and executes a single SQL statement. Returns the number of rows affected or undef on error. A return value of -1 means the number of rows is not known, not applicable, or not available. Here $dbh is a handle returned by DBI->connect() call. 3 $dbh->prepare($sql) This routine prepares a statement for later execution by the database engine and returns a reference to a statement handle object. 4 $sth->execute() This routine performs whatever processing is necessary to execute the prepared statement. An undef is returned if an error occurs. A successful execute always returns true regardless of the number of rows affected. Here, $sth is a statement handle returned by $dbh->prepare($sql) call. 5 $sth->fetchrow_array() This routine fetches the next row of data and returns it as a list containing the field values. Null fields are returned as undef values in the list. 6 $DBI::err This is equivalent to $h->err, where $h is any of the handle types like $dbh, $sth, or $drh. This returns native database engine error code from the last driver method called. 7 $DBI::errstr This is equivalent to $h->errstr, where $h is any of the handle types like $dbh, $sth, or $drh. This returns the native database engine error message from the last DBI method called. 8 $dbh->disconnect() This routine closes a database connection previously opened by a call to DBI->connect(). Connecting To Database Following Perl code shows how to connect to an existing database. If database does not exist, then it will be created and finally a database object will be returned. #!/usr/bin/perl
- 161. TUTORIALS POINT Simply Easy Learning use DBI; use strict; my $driver = "SQLite"; my $database = "test.db"; my $dsn = "DBI:$driver:dbname=$database"; my $userid = ""; my $password = ""; my $dbh = DBI->connect($dsn, $userid, $password, { RaiseError => 1 }) or die $DBI::errstr; print "Opened database successfullyn"; Now, let's run above program to create our database test.db in the current directory. You can change your path as per your requirement. Keep above code in sqlite.pl file and execute it as shown below. If database is successfully created, then it will give the following message: $ chmod +x sqlite.pl $ ./sqlite.pl Open database successfully Create a Table Following Perl program will be used to create a table in previously created database: #!/usr/bin/perl use DBI; use strict; my $driver = "SQLite"; my $database = "test.db"; my $dsn = "DBI:$driver:dbname=$database"; my $userid = ""; my $password = ""; my $dbh = DBI->connect($dsn, $userid, $password, { RaiseError => 1 }) or die $DBI::errstr; print "Opened database successfullyn"; my $stmt = qq(CREATE TABLE COMPANY (ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL);); my $rv = $dbh->do($stmt); if($rv < 0){ print $DBI::errstr; } else { print "Table created successfullyn"; } $dbh->disconnect(); When above program is executed, it will create COMPANY table in your test.db and it will display the following messages: Opened database successfully Table created successfully
- 162. TUTORIALS POINT Simply Easy Learning NOTE: in case you see following error in any of the operation: DBD::SQLite::st execute failed: not an error(21) at dbdimp.c line 398 In this case you will have open dbdimp.c file available in DBD-SQLite installation and find out sqlite3_prepare() function and change its third argument to -1 instead of 0. Finally install DBD::SQLite using make and do make install to resolve the problem. INSERT Operation Following Perl program shows how we can create records in our COMPANY table created in above example: #!/usr/bin/perl use DBI; use strict; my $driver = "SQLite"; my $database = "test.db"; my $dsn = "DBI:$driver:dbname=$database"; my $userid = ""; my $password = ""; my $dbh = DBI->connect($dsn, $userid, $password, { RaiseError => 1 }) or die $DBI::errstr; print "Opened database successfullyn"; my $stmt = qq(INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (1, 'Paul', 32, 'California', 20000.00 )); my $rv = $dbh->do($stmt) or die $DBI::errstr; $stmt = qq(INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (2, 'Allen', 25, 'Texas', 15000.00 )); $rv = $dbh->do($stmt) or die $DBI::errstr; $stmt = qq(INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (3, 'Teddy', 23, 'Norway', 20000.00 )); $rv = $dbh->do($stmt) or die $DBI::errstr; $stmt = qq(INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 );); $rv = $dbh->do($stmt) or die $DBI::errstr; print "Records created successfullyn"; $dbh->disconnect(); When above program is executed, it will create given records in COMPANY table and will display the following two lines: Opened database successfully Records created successfully SELECT Operation Following Perl program shows how we can fetch and display records from our COMPANY table created in above example: #!/usr/bin/perl use DBI; use strict;
- 163. TUTORIALS POINT Simply Easy Learning my $driver = "SQLite"; my $database = "test.db"; my $dsn = "DBI:$driver:dbname=$database"; my $userid = ""; my $password = ""; my $dbh = DBI->connect($dsn, $userid, $password, { RaiseError => 1 }) or die $DBI::errstr; print "Opened database successfullyn"; my $stmt = qq(SELECT id, name, address, salary from COMPANY;); my $sth = $dbh->prepare( $stmt ); my $rv = $sth->execute() or die $DBI::errstr; if($rv < 0){ print $DBI::errstr; } while(my @row = $sth->fetchrow_array()) { print "ID = ". $row[0] . "n"; print "NAME = ". $row[1] ."n"; print "ADDRESS = ". $row[2] ."n"; print "SALARY = ". $row[3] ."nn"; } print "Operation done successfullyn"; $dbh->disconnect(); When above program is executed, it will produce the following result: Opened database successfully ID = 1 NAME = Paul ADDRESS = California SALARY = 20000 ID = 2 NAME = Allen ADDRESS = Texas SALARY = 15000 ID = 3 NAME = Teddy ADDRESS = Norway SALARY = 20000 ID = 4 NAME = Mark ADDRESS = Rich-Mond SALARY = 65000 Operation done successfully UPDATE Operation Following Perl code shows how we can use UPDATE statement to update any record and then fetch and display updated records from our COMPANY table: #!/usr/bin/perl use DBI; use strict;
- 164. TUTORIALS POINT Simply Easy Learning my $driver = "SQLite"; my $database = "test.db"; my $dsn = "DBI:$driver:dbname=$database"; my $userid = ""; my $password = ""; my $dbh = DBI->connect($dsn, $userid, $password, { RaiseError => 1 }) or die $DBI::errstr; print "Opened database successfullyn"; my $stmt = qq(UPDATE COMPANY set SALARY = 25000.00 where ID=1;); my $rv = $dbh->do($stmt) or die $DBI::errstr; if( $rv < 0 ){ print $DBI::errstr; }else{ print "Total number of rows updated : $rvn"; } $stmt = qq(SELECT id, name, address, salary from COMPANY;); my $sth = $dbh->prepare( $stmt ); $rv = $sth->execute() or die $DBI::errstr; if($rv < 0){ print $DBI::errstr; } while(my @row = $sth->fetchrow_array()) { print "ID = ". $row[0] . "n"; print "NAME = ". $row[1] ."n"; print "ADDRESS = ". $row[2] ."n"; print "SALARY = ". $row[3] ."nn"; } print "Operation done successfullyn"; $dbh->disconnect(); When above program is executed, it will produce the following result: Opened database successfully Total number of rows updated : 1 ID = 1 NAME = Paul ADDRESS = California SALARY = 25000 ID = 2 NAME = Allen ADDRESS = Texas SALARY = 15000 ID = 3 NAME = Teddy ADDRESS = Norway SALARY = 20000 ID = 4 NAME = Mark ADDRESS = Rich-Mond SALARY = 65000 Operation done successfully
- 165. TUTORIALS POINT Simply Easy Learning DELETE Operation Following Perl code shows how we can use DELETE statement to delete any record and then fetch and display remaining records from our COMPANY table: #!/usr/bin/perl use DBI; use strict; my $driver = "SQLite"; my $database = "test.db"; my $dsn = "DBI:$driver:dbname=$database"; my $userid = ""; my $password = ""; my $dbh = DBI->connect($dsn, $userid, $password, { RaiseError => 1 }) or die $DBI::errstr; print "Opened database successfullyn"; my $stmt = qq(DELETE from COMPANY where ID=2;); my $rv = $dbh->do($stmt) or die $DBI::errstr; if( $rv < 0 ){ print $DBI::errstr; }else{ print "Total number of rows deleted : $rvn"; } $stmt = qq(SELECT id, name, address, salary from COMPANY;); my $sth = $dbh->prepare( $stmt ); $rv = $sth->execute() or die $DBI::errstr; if($rv < 0){ print $DBI::errstr; } while(my @row = $sth->fetchrow_array()) { print "ID = ". $row[0] . "n"; print "NAME = ". $row[1] ."n"; print "ADDRESS = ". $row[2] ."n"; print "SALARY = ". $row[3] ."nn"; } print "Operation done successfullyn"; $dbh->disconnect(); When above program is executed, it will produce the following result: Opened database successfully Total number of rows deleted : 1 ID = 1 NAME = Paul ADDRESS = California SALARY = 25000 ID = 3 NAME = Teddy ADDRESS = Norway SALARY = 20000 ID = 4 NAME = Mark ADDRESS = Rich-Mond SALARY = 65000
- 166. TUTORIALS POINT Simply Easy Learning SQLite Python Installation The SQLite3 can be integrated with Python using sqlite3 module, which was written by Gerhard Haring. It provides an SQL interface compliant with the DB-API 2.0 specification described by PEP 249. You do not need to install this module separately because its being shipped by default along with Python version 2.5.x onwards. To use sqlite3 module, you must first create a connection object that represents the database and then optionally you can create cursor object, which will help you in executing all the SQL statements. Python sqlite3 module APIs Following are important sqlite3 module routines, which can suffice your requirement to work with SQLite database from your Perl program. If you are looking for a more sophisticated application, then you can look into Python sqlite3 module's official documentation. S.N. API & Description 1 sqlite3.connect(database [,timeout ,other optional arguments]) This API opens a connection to the SQLite database file database. You can use ":memory:" to open a database connection to a database that resides in RAM instead of on disk. If database is opened successfully, it returns a connection object. When a database is accessed by multiple connections, and one of the processes modifies the database, the SQLite database is locked until that transaction is committed. The timeout parameter specifies how long the connection should wait for the lock to go away until raising an exception. The default for the timeout parameter is 5.0 (five seconds). If given database name does not exist then this call will create the database. You can specify filename with required path as well if you want to create database anywhere else except in current directory. 2 connection.cursor([cursorClass]) This routine creates a cursor which will be used throughout of your database programming with Python. This method accepts a single optional parameter cursorClass. If supplied, this must be a custom cursor class that extends sqlite3.Cursor. 3 cursor.execute(sql [, optional parameters]) CHAPTER 50
- 167. TUTORIALS POINT Simply Easy Learning This routine executes an SQL statement. The SQL statement may be parameterized (i. e. placeholders instead of SQL literals). The sqlite3 module supports two kinds of placeholders: question marks and named placeholders (named style). For example:cursor.execute("insert into people values (?, ?)", (who, age)) 4 connection.execute(sql [, optional parameters]) This routine is a shortcut of the above execute method provided by cursor object and it creates an intermediate cursor object by calling the cursor method, then calls the cursor's execute method with the parameters given. 5 cursor.executemany(sql, seq_of_parameters) This routine executes an SQL command against all parameter sequences or mappings found in the sequence sql. 6 connection.executemany(sql[, parameters]) This routine is a shortcut that creates an intermediate cursor object by calling the cursor method, then calls the cursor.s executemany method with the parameters given. 7 cursor.executescript(sql_script) This routine executes multiple SQL statements at once provided in the form of script. It issues a COMMIT statement first, then executes the SQL script it gets as a parameter. All the SQL statements should be separated by semi colon (;). 8 connection.executescript(sql_script) This routine is a shortcut that creates an intermediate cursor object by calling the cursor method, then calls the cursor's executescript method with the parameters given. 9 connection.total_changes() This routine returns the total number of database rows that have been modified, inserted, or deleted since the database connection was opened. 10 connection.commit() This method commits the current transaction. If you don.t call this method, anything you did since the last call to commit() is not visible from other database connections. 11 connection.rollback() This method rolls back any changes to the database since the last call to commit(). 12 connection.close() This method closes the database connection. Note that this does not automatically call commit(). If you
- 168. TUTORIALS POINT Simply Easy Learning just close your database connection without calling commit() first, your changes will be lost! 13 cursor.fetchone() This method fetches the next row of a query result set, returning a single sequence, or None when no more data is available. 14 cursor.fetchmany([size=cursor.arraysize]) This routine fetches the next set of rows of a query result, returning a list. An empty list is returned when no more rows are available. The method tries to fetch as many rows as indicated by the size parameter. 15 cursor.fetchall() This routine fetches all (remaining) rows of a query result, returning a list. An empty list is returned when no rows are available. Connecting To Database Following Python code shows how to connect to an existing database. If database does not exist, then it will be created and finally a database object will be returned. #!/usr/bin/python import sqlite3 conn = sqlite3.connect('test.db') print "Opened database successfully"; Here, you can also supply database name as the special name :memory: to create a database in RAM. Now, let's run above program to create our database test.db in the current directory. You can change your path as per your requirement. Keep above code in sqlite.py file and execute it as shown below. If database is successfully created, then it will give the following message: $chmod +x sqlite.py $./sqlite.py Open database successfully Create a Table Following Python program will be used to create a table in previously created database: #!/usr/bin/python import sqlite3 conn = sqlite3.connect('test.db') print "Opened database successfully"; conn.execute('''CREATE TABLE COMPANY (ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL,
- 169. TUTORIALS POINT Simply Easy Learning ADDRESS CHAR(50), SALARY REAL);''') print "Table created successfully"; conn.close() When above program is executed, it will create COMPANY table in your test.db and it will display the following messages: Opened database successfully Table created successfully INSERT Operation Following Python program shows how we can create records in our COMPANY table created in above example: #!/usr/bin/python import sqlite3 conn = sqlite3.connect('test.db') print "Opened database successfully"; conn.execute("INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (1, 'Paul', 32, 'California', 20000.00 )"); conn.execute("INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (2, 'Allen', 25, 'Texas', 15000.00 )"); conn.execute("INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (3, 'Teddy', 23, 'Norway', 20000.00 )"); conn.execute("INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 )"); conn.commit() print "Records created successfully"; conn.close() When above program is executed, it will create given records in COMPANY table and will display the following two lines: Opened database successfully Records created successfully SELECT Operation Following Python program shows how we can fetch and display records from our COMPANY table created in above example: #!/usr/bin/python import sqlite3 conn = sqlite3.connect('test.db') print "Opened database successfully"; cursor = conn.execute("SELECT id, name, address, salary from COMPANY") for row in cursor:
- 170. TUTORIALS POINT Simply Easy Learning print "ID = ", row[0] print "NAME = ", row[1] print "ADDRESS = ", row[2] print "SALARY = ", row[3], "n" print "Operation done successfully"; conn.close() When above program is executed, it will produce the following result: Opened database successfully ID = 1 NAME = Paul ADDRESS = California SALARY = 20000.0 ID = 2 NAME = Allen ADDRESS = Texas SALARY = 15000.0 ID = 3 NAME = Teddy ADDRESS = Norway SALARY = 20000.0 ID = 4 NAME = Mark ADDRESS = Rich-Mond SALARY = 65000.0 Operation done successfully UPDATE Operation Following Python code shows how we can use UPDATE statement to update any record and then fetch and display updated records from our COMPANY table: #!/usr/bin/python import sqlite3 conn = sqlite3.connect('test.db') print "Opened database successfully"; conn.execute("UPDATE COMPANY set SALARY = 25000.00 where ID=1") conn.commit print "Total number of rows updated :", conn.total_changes cursor = conn.execute("SELECT id, name, address, salary from COMPANY") for row in cursor: print "ID = ", row[0] print "NAME = ", row[1] print "ADDRESS = ", row[2] print "SALARY = ", row[3], "n" print "Operation done successfully"; conn.close() When above program is executed, it will produce the following result:
- 171. TUTORIALS POINT Simply Easy Learning Opened database successfully Total number of rows updated : 1 ID = 1 NAME = Paul ADDRESS = California SALARY = 25000.0 ID = 2 NAME = Allen ADDRESS = Texas SALARY = 15000.0 ID = 3 NAME = Teddy ADDRESS = Norway SALARY = 20000.0 ID = 4 NAME = Mark ADDRESS = Rich-Mond SALARY = 65000.0 Operation done successfully DELETE Operation Following Python code shows how we can use DELETE statement to delete any record and then fetch and display remaining records from our COMPANY table: #!/usr/bin/python import sqlite3 conn = sqlite3.connect('test.db') print "Opened database successfully"; conn.execute("DELETE from COMPANY where ID=2;") conn.commit print "Total number of rows deleted :", conn.total_changes cursor = conn.execute("SELECT id, name, address, salary from COMPANY") for row in cursor: print "ID = ", row[0] print "NAME = ", row[1] print "ADDRESS = ", row[2] print "SALARY = ", row[3], "n" print "Operation done successfully"; conn.close() When above program is executed, it will produce the following result: Opened database successfully Total number of rows deleted : 1 ID = 1 NAME = Paul ADDRESS = California SALARY = 20000.0
- 172. TUTORIALS POINT Simply Easy Learning ID = 3 NAME = Teddy ADDRESS = Norway SALARY = 20000.0 ID = 4 NAME = Mark ADDRESS = Rich-Mond SALARY = 65000.0 Operation done successfully