SQL python for beginners easy explanation with concepts and output .pptx

SPRINGDALES SCHOOL
DHAULA KUAN
COMPUTER SCIENCE
STD.XII

SQL – Structured Query Language
 Is a language that enables you to create and operate
on relational databases
 It is the standard language used by almost all
the database s/w vendors.
 Pronounced as SEQUEL
 Original version was developed by IBM’s
Almanden Research Center
 Latest ISO standard of SQL was released in 2008 and
named as SQL:2008

SQL –features
 Allows creating/modifying a database’s structure
 Changing security settings for system
 Permitting users for working on databases or tables
 Querying database
 Inserting/modifying/deleting the database contents

MYSQL Elements
 Literals
 Data types
 Nulls
 Comments

Literals
 It means the fixed value or constant value. It may be of
character, numeric or date time type.
 Character and date/time literals are always in single
quotation marks whereas numeric literals must be
without single quotation marks
 For example – ‘Virat’, 12, 12.56, ‘04-20-2018’
format
 Date and time values are always in
the YYYY-MM-DD HH:MI:SS
 Special character like quotes are always written be
preceding it back-slash(). For example if we want to
store value as Tom’s Cat then it should be written as
Tom’s Cat

Data Type
 Means the type of value and type of operation we
can perform on data. For example on numeric value
we can store numbers and perform all arithmetic
operations and so on.
 MySQL support three categories of data types:
Numeric
Date and time
String types

Numeric Data Types
Data type Description
INT Numbers without decimal. Store up to 11 digits. -2147483648 to 2147483647
TINYINT Small integer value between 0 – 255 (4 digits)
SMALLINT More than TINYINT between -32768 to 32767 (5 digit)
MEDIUMINT Integer values up to 9 digits
BIGINT Very large integer value up to 11 digits
FLOAT(M,D) Real numbers i.e. number with decimal. M specify length of numeric value
including decimal place D and decimal symbol. For example if it is given as
FLOAT(8,2) then 5 integer value 1 decimal symbol and 2 digit after decimal
TOTAL – 8. it can work on 24 digits after decimal.
DOUBLE(M,D) Real numbers with more precision up to 53 place after decimal.
DECIMAL It is used to store exact numeric value that preserve exact precision for e.g.
money data in accounting system.
DECIMAL(P,D) means P no. of significant digits (1-65), D represent no. of digit
after decimal(0-30), for e.g DECIMAL(6,2) means 4 digit before decimal and 2
digit after decimal. Max will be 9999.99

Date and Time Types
DATE A date in YYY-MM-DD format between 1000-01-01 to 9999-12-31
In oracle data format is DD-MON-YYYY for e.g 10-SEP-2019
DATETIME Combination of date and time. For example to store 4th December
2018 and time is afternoon 3:30 then it should be written as –
2018-12-04 15:30:00
TIMESTAMP Similar to DATATIME but it is written without hyphen for example the
above date time is stored as 20181204153000
TIME To store time in the format HH:MM:SS
YEAR(M) To store only year part of data where M may be 2 or 4 i.e. year in 2
digit like 18 or 4 digit like 2018

String Types
CHAR(M) Fixed length string between 1 and 255. it always occupy M size for each data for
example if size is CHAR(20) and we store value ‘MOBILE’ , although the size of
MOBILE is 6 but in a table it will occupy 20 size with space padded at right side
for remaining place.
Mostly use in the case where the data to be insert is of fixed size like Grade
(A,B,C,..) or Employee code as E001, E002, etc. In this case CHAR will give better
performance than varchar
VARCHAR(M) Variable length string between 1 and 65535 (from MySQL 5.0.3) , earlier it was
255. it takes size as per the data entered for example with VARCHAR(20) if the
data entered is MOBILE then it will take only 6 byte. It is useful for the data like
name, address where the number of character to be enter is not fixed.
VARCHAR2 It is supported in ORACLE, both are almost same with minor difference. The
difference is in the way they are handling Empty String and NULL, for VARCHAR
these two are different where as VARCHAR2 treats both same.

Difference between
CHAR & VARCHAR
CHAR VARCHAR
Fixed length string Variable length string
Used where number of character to enter
is fixed like Grade, EmpCode, etc
Used where number of character to be
enter is not fixed like name, address etc.
Fast, no memory allocation every time Slow, as it take size according to data so
every time memory allocation is done
It takes more memory It takes less space

NULL VALUE
• NULL means missing information
• NULL can appear in any type of column if it is not restricted by
NOT NULL or PRIMARY KEY
• Always remember NULL is neither equal to 0 nor space. NULL
means nothing
• Used in situation like if email id is not available with students
then we will insert NULL

COMMENTS
• It is a text that is not executed, only for
documentation purpose. Comments in MySQL
can be written as
– Begin the comment with /* and */
– Begin the comment with – (followed by space)
– Begin then comment with #
• For example
– /* Select * from emp where empno=4 */
– Select * from emp; -- it will fetch all details

SQL COMMAND SYNTAX
Commands Description
Keywords That have special meaning in SQL. They are the commands in mysql
Clause They are used to support mysql commands like FROM, WHERE etc.
Arguments Values passed to clause like table name to FROM clause conditions to
WHERE clause for e.g.
SELECT * FROM EMP WHERE SALARY>12000;
In the above command
SELECT is keyword
FROM AND WHERE is clause
EMP is an argument to FROM
SALARY>12000 is argument
to WHERE

CREATING and USING DATABASE
CREATE DATABASE <DATABASE NAME>
CREATE DATABASE MYDB;
TO SEE LIST OF DATABASES:
SHOW DATABASES;
TO OPEN ANY DATABASE TO WORK
USE DATABASENAME;
USE MYDB;

TABLE CONSTRAINTS
1. Primary Key Constraint
2. Unique Constraint
3. Check Constraint
4. Default Constraint
5. NOT NULL Constraint

Difference between Primary Key
and Unique Constraint
Primary Key Constraint Unique Constraint
There is only one Primary key There can be more than one
NULL values are not possible NULL values are possible

CREATING TABLE
datatype(size),
Syntax:-
Create Table TableName(ColumnName ColumnName
datatype(size),…..);
Example:-
Create Table Employee(empno int primary key, name
varchar(20), dept varchar(20), salary int);
Create table Student(roll int, name varchar(20),
stream varchar(20), per int);

CREATING TABLE
Create Table Employee(empno int primary key, name
varchar(20), dept varchar(20), salary int);
Empno Name Dept Salary
1 Ravi Sales 24000
2 Sunny Sales 35000
3 Shobit IT 30000
4 Vikram IT 27000
5 nitin HR 45000
6 Krish HR

SHOWING TABLE
TO SEE LIST OF TABLES IN THE DATABASE
SHOW TABLES;

SHOWING TABLE STRUCTURE
TO SEE STRUCTURE OF TABLE:
It specifies the fields, data types and constraints used in the table.
DESC TABLENAME;
OR
DESCRIBE TABLENAME;
EXAMPLE:
DESC EMPLOYEE;
DESC STUDENT;

 MySQL allows us to get the structure of table
like list of columns, data type, size and key
information of table using DESC / DESCRIBE
command
 Example

INSERTING RECORDS IN TABLE
Syntax:-
Insert into tablename values(value1,value2,…)
Note:-
1) char, varchar and date value must be in single
quotes
2) Values must be passed in the order of their column
3) Date values are passed in the format
yyyy-mm-dd (in mysql)

Syntax:-
Insert into emp values(1, ‘Ravi’,’Sales’,24000)
Insert into student values(1,’Mahi’,’Science’,89);
Inserting in selected columns
Insert into emp (empno, name, dept ) values
(2,’dipanker’,’IT’)

Syntax:-
Insert into emp values(1, ‘Ravi’,’Sales’,24000);
1 Ravi Sales 24000
2 Sunny Sales 35000
3 Shobit IT 30000
4 Vikram IT 27000
5 nitin HR 45000
6 Krish HR

SELECTING RECORD
Select statement allows to send queries to table and
fetch the desired record. Select can be used to select
both horizontal and vertical subset.
Syntax:-
Select * / columnnames FROM
tablename
[ where condition ];

SELECTING RECORD
Selecting all record and all columns
Select * from emp;
Selecting desired columns
select empno, name from emp;
Changing the order of columns
select dept, name from emp;

SELECTING RECORD
Selecting all record and all columns
Select * from emp;
1 Ravi Sales 24000
2 Sunny Sales 35000
3 Shobit IT 30000
4 Vikram IT 27000
5 nitin HR 45000
6 Krish HR

SELECTING RECORD
Selecting desired columns
select empno, name from emp;
Empno Name
1 Ravi
2 Sunny
3 Shobit
4 Vikram
5 nitin
6 Krish

ALL keyword
ALL keyword is used to see the duplicate records from output
For e.g. if we select dept from employee table it will display all the
department from the table including duplicate rows.
ALL is the default , so using it is optional.
Select ALL dept from emp;
Output will be:-
Dept
--------
Sale
Sale
IT
IT
HR
1 Ravi Sale 24000
2 Sunny Sale 35000
3 Shobit IT 30000
4 Vikram IT 27000
5 nitin HR 45000

DISTINCT keyword
DISTINCT keyword is used to eliminate the duplicate records from
output. If we don’t want to see the duplicate rows in output we
have to use DISTINCT keyword.
Select DISTINCT dept from emp;
Output will be:-
Dept
--------
Sale
IT
HR
1 Ravi Sale 24000
2 Sunny Sale 35000
3 Shobit IT 30000
4 Vikram IT 27000
5 nitin HR 45000

PERFORMING SIMPLE CALCULATION
While performing SQL operations sometimes simple
calculations are required, SQL provides facility to perform
simple arithmetic operations in query. In MySQL we can
give these queries without FROM clause i.e. table name
is not required for these queries,
For Example:
Select 10*2;
Select 10*3/6;

PERFORMING SIMPLE CALCULATION
MySQL also provides DUAL table to provide compatibility with
other DBMS. It is dummy table used for these type queries where
table name is not required. It contains one row and one column.
For example:
Select 100+200 from DUAL;
Select curdate( ) from dual;
CALCULATION WITH TABLE DATA
Select name, salary, salary * 12 Annual_Salary from emp;
Select empno, salary+1000 from emp;
Update student set total=phy+chem+maths+cs+eng;

COLUMN ALIAS
It is a temporary name/label given to column that will appear in
output. For example if column name is dept and you want
Department to appear as column heading then we have to give
Column Alias. If we want alias name of multiple words then it
should be enclosed in double quotes. Its format is :
ColumnName [AS] ColumnAlias
Example
(i)Select empno Employee_Number, name, dept Department,
Salary Income from emp;
(ii) Select name, Salary*12 as “Annual Income” from emp;

HANDLING NULL
VINOD
KUMAR
VERMA,
PGT(CS),
KV
OEF
KANPUR
&
SACHIN
BHARDWAJ,
PGT(CS),
KV
NO.1
TEZPUR
From the above table we can observe that salary of Shaban is NULL i.e.
not assigned, Now if we want 0 or “not assigned” for the salary
information of shaban, we have to use IFNULL()
Select empno,name,IFNULL(Salary,”not assigned”) from emp;
Column value to substitute if
NULL found

PUTTING TEXT IN QUERY OUTPUT
SQL allows to put user defined symbols or text with table output.
Like ‘Rs’ with Salary or ‘%’ symbol with commission
For e.g.
Select name, dept, ‘Rs.’, salary from emp;
Select name, ‘ works in department’, dept, ‘ and getting salary rs.
‘, salary from emp;
Select name, concat(‘Rs. ‘, salary) from emp;

WHERE clause
WHERE clause is used to select specified rows.
It allows to select only desired rows by applying condition.
We can use all comparison(>, <, >=, <=, =, <>) and logical
operator (AND, OR, NOT).
AND ( &&), OR (||) , NOT (!)
For example
Select * from emp where salary>4000;
Select * from emp where empno=1;
Select name,dept from emp where
dept=‘HR’;

WHERE clause
Selecting desired columns and rows:
select empno, name from emp where Empno=2;
Empno Name
2 Sunny

WHERE clause
AND(&&) means both conditions must be true, OR(||) means
any condition must be true to produce output. NOT(!) will do
the reverse checking.
Select * from emp where salary>4000 and salary<8000;
Select * from emp where dept=‘Sales’ and salary<30000;
Select name,dept from emp where dept=‘HR’ and
salary>=20000 and salary<=40000;
Select * from emp where dept=‘HR’ or dept=‘IT’;
Select * from emp where NOT empno=4;

WHERE clause
Select * from emp where dept=‘Sale’ and salary<30000;
1 Ravi Sale 24000

SQL operators
1) BETWEEN
2) IN
3) LIKE
4) IS NULL

BETWEEN
BETWEEN allows to specify range of values to search in any column. It
is used with AND clause and it will include the specified values during
the searching.
For e.g.
Select * from emp where salary between 18000 and 30000; Select
name from emp where empno between 2 and 5;
Select * from emp where salary NOT between 25000 and 35000;

BETWEEN
Select * from emp where salary between 18000 and 30000;
OR
Select * from emp where salary >= 18000 AND salary <= 30000;
1 Ravi Sale 24000
3 Shobit IT 30000
4 Vikram IT 27000

IN
IN allows to specify LIST of values in which searching will be
performed. It will return all those record that matches any
value in a given list of values. It can be thought as an
alternative of multiple ORs
Select * from emp where dept IN(‘sales’,’it’);
Select name from emp where empno IN (2,4,5); Select *
from emp where dept NOT IN(‘sales’,’it’)

IN
Select * from emp where dept IN(‘sales’,’it’);
OR
Select * from emp where dept =‘sales’ OR dept=’it’;
1 Ravi Sale 24000
2 Sunny Sale 35000
3 Shobit IT 30000
4 Vikram IT 27000

LIKE
LIKE allows to search based on pattern. It is used when
we don’t want to search an exact value or we don’t know
that exact value, and we know only the pattern of value
like name starting from any particular letter, or ending
with and containing any particular letter or word.
LIKE is used with two wildcard characters:
a) % : used when we want to substitute
multiple characters. With % length is not fixed.
b) _ (underscore) : used when we want to
substitute Single character.

LIKE
Search for employee whose name begins from ‘S’
Select * from emp where name like ‘S%’;
Search for employee whose name ends with ‘r’
Select * from emp where name like ‘%r’;
Search for employee whose name contains ‘a’ anywhere
Select * from emp where name like ‘%a%’
Search for employee whose dob is in feb(dd-mm-yy)
Select * from emp where dob like ‘%-02-%’
Search employee whose name is of 5 letters begins from ‘s’
Select * from emp where name like ‘s_ _ _ _ ’;

LIKE
Search for employee whose name begins from ‘s’
Select * from emp where name like ‘S%’;
2 Sunny Sale 35000
3 Shobit IT 30000

IS NULL
IS NULL is used to compare NULL values present in any
column. Because NULL is not considered as value so we
cannot compare with = sign, so to compare with NULL , SQL
provides IS NULL.
Select * from emp where salary is null; Select
* from emp where salary is not null;

SORTING OUTPUT
By default records will come in the output in the same order
in which it was entered. To see the output rows in sorted or
arranged in ascending or descending order ,SQL provide
ORDER BY clause.
By default output will be ascending order(ASC) to see output
in descending order we use DESC clause with ORDER BY.
Select * from emp order by name; (ascending order)
Select * from emp order by salary desc; (descending
order)
Select * from emp order by dept asc, salary desc;

SORTING OUTPUT
Select * from emp order by salary desc;
5 nitin HR 45000
2 Sunny Sale 35000
3 Shobit IT 30000
4 Vikram IT 27000
1 Ravi Sale 24000

JUST A MINUTE…
• Create the following table and add the records
in ITEMS table:
ItemNo Item Dcode Qty UnitPrice StockDate
5005 Ball Pen 0.5 102 100 16 2018-03-10
5003 Ball Pen 0.25 102 150 20 2017-05-17
5002 Gel Pen Premium 101 125 14 2018-04-20
5006 Gel Pen Classic 101 200 22 2018-10-08
5001 Eraser Small 102 210 5 2018-03-11
5004 Eraser Big 102 60 10 2017-11-18
5009 Sharpener Classic NULL 160 8 2017-06-12

JUST A MINUTE…
Write down the following queries based on the given table:
1) Select all record of table
2) Select ItemNo, name and Unitprice
3) Select all item record where Unitprice is more than 20
4) Select Item name of those items which are quantity
between 100-200
5) Select all record of Items which contains ‘pen‘ word in it
6) Select unique dcode of all items
7) Display all record in the descending order of UnitPrice

OPERATOR PRECEDENCE
When multiple operators are used in expression, then
evaluation of expression takes place in the order of
precedence. Higher precedence operator will execute
first. !
*, /, DIV, %, MOD
- +
<, >
==, >=, <=, !=, IS, LIKE, IN, BETWEEN
NOT
AND
OR
HIGH
LOW

AGGREGATE functions
Aggregate function is used to perform calculation on group of rows
and return the calculated summary like sum of salary, average of
salary etc.
Available aggregate functions are –
1. SUM()
2. AVG()
3. COUNT()
4. MAX()
5. MIN()
6. COUNT(*)

AGGREGATE functions
Select SUM(salary) from emp;
Output – 161000
Select SUM(salary) from emp where dept=‘sales’;
Output - 59000
1 Ravi Sales 24000
2 Sunny Sales 35000
3 Shobit IT 30000
4 Vikram IT 27000
5 nitin HR 45000

AGGREGATE functions
Select AVG(salary) from emp;
Output – 32200
Select AVG(salary) from emp where dept=‘sales’;
Output - 29500
1 Ravi Sales 24000
2 Sunny Sales 35000
3 Shobit IT 30000
4 Vikram IT 27000
5 nitin HR 45000

AGGREGATE functions
Select COUNT(name) from emp;
Output – 5
Select COUNT(salary) from emp where dept=‘HR’;
Output - 1
Select COUNT(DISTINCT dept) from emp;
Output - 3
1 Ravi Sales 24000
2 Sunny Sales 35000
3 Shobit IT 30000
4 Vikram IT 27000
5 nitin HR 45000

AGGREGATE functions
Select MAX(Salary) from emp;
Output – 45000
Select MAX(salary) from emp where dept=‘Sales’;
Output - 35000
1 Ravi Sales 24000
2 Sunny Sales 35000
3 Shobit IT 30000
4 Vikram IT 27000
5 nitin HR 45000

AGGREGATE functions
Select MIN(Salary) from emp;
Output – 24000
Select MIN(salary) from emp where dept=‘IT’;
Output - 27000
1 Ravi Sales 24000
2 Sunny Sales 35000
3 Shobit IT 30000
4 Vikram IT 27000
5 nitin HR 45000

AGGREGATE functions
Select COUNT(*) from emp;
Output – 6
Select COUNT(salary) from emp;
Output - 5
1 Ravi Sales 24000
2 Sunny Sales 35000
3 Shobit IT 30000
4 Vikram IT 27000
5 nitin HR 45000
6 Krish HR

count(*) Vs count()
Count(*) function is used to count the number of rows in query
output whereas count() is used to count values present in any
column excluding NULL values.
Note:
All aggregate function ignores the NULL values.
Give previous example.

GROUP BY
GROUP BY clause is used to divide the table into logical groups and
we can perform aggregate functions in those groups. In this case
aggregate function will return output for each group. For example
if we want sum of salary of each department we have to divide
table records.

Aggregate functions by default takes the entire table as a single group that’s why
we are getting the sum(), avg(), etc output for the entire table. Now suppose
organization wants the sum() of all the job separately, or wants to find the average
salary of every job. In this case we have to logically divide our table into groups
based on job, so that every group will be passed to aggregate function for
calculation and aggregate function will return the result for every group.

column value. In those logically divided records we can
apply aggregate functions.
For. E.g.
SELECT SUM(SAL) FROM EMP GROUP BY DEPT; SELECT
JOB,SUM(SAL) FROM EMP GROUP BY DEPT; SELECT
JOB,SUM(SAL),AVG(SAL),MAX(SAL),COUNT(*)
EMPLOYEE_COUNT FROM EMP;
NOTE :- when we are using GROUP BY we can use only aggregate function and the
column on which we are grouping in the SELECT list because they will form a group other
than any column will gives you an error because they will be not the part of the group.
For e.g.
SELECT ENAME,JOB,SUM(SAL) FROM EMP GROUP BY JOB;
Error -> because Ename is not a group expression
Group by clause helps up to divide the table into logical groups based

HAVING with GROUP BY
• If we want to filter or restrict some rows from the output produced by
GROUP BY then we use HAVING clause. It is used to put condition of group of
rows. With having clause we can use aggregate functions also.
• WHERE is used before the GROUP BY. With WHERE we cannot use aggregate
function.
• E.g.
• SELECT DEPT,AVG(SAL) FROM EMP GROUP BY DEPT HAVING
DEPT IN (‘HR’,’SALES’)
• SELECT DEPT,MAX(SAL),MIN(SAL),COUNT(*) FROM EMP
GROUP BY DEPT HAVING COUNT(*)>1
• SELECT DEPT,MAX(SAL),MIN(SAL) FROM EMP WHERE
SAL>=2000 GROUP BY DEPT HAVING DEPT IN(‘IT’,’HR’)

JUST A MINUTE…
• Create the following table and add the records
ItemNo Item Dcode Qty UnitPrice StockDate
5005 Ball Pen 0.5 102 100 16 2018-03-10
5003 Ball Pen 0.25 102 150 20 2017-05-17
5002 Gel Pen Premium 101 125 14 2018-04-20
5006 Gel Pen Classic 101 200 22 2018-10-08
5001 Eraser Small 102 210 5 2018-03-11
5004 Eraser Big 102 60 10 2017-11-18
5009 Sharpener Classic NULL 160 8 2017-06-12

JUST A MINUTE…
Write down the following queries based on the given table:
1. Change the unitprice to 20 for itemno 5005
2. Delete the record of itemno 5001
3. Display all the item name in capital letters
4. Display first 4 character of every item name
5. Display all record whose dcode is not assigned
6. Display all items which are stocked in the month of
March

MYSQL FUNCTIONS
A function is built – in code for specific purpose that
takes value and returns a single value. Values passed to
functions are known as arguments/parameters.
There are various categories of function in MySQL:-
1) String Function
2) Mathematical function
3) Date and time function

String Function
Function Description Example
ASCII( ) Returns the ASCII
value of the
character
Select ascii(‘A’);
Output- 65
CHAR( ) Return character
for given ASCII
Code
Select char(65);
Output- A
CONCAT( ) Return concatenated
string
Select concat(name, ‘ works in ‘, dept,’
department);
LOWER()/
LCASE( )
Return string in
small letters
Select lower(‘INDIA’); Output- india
Select lower(name) from emp;
SUBSTRING(
S,P,N) /
MID(S,P,N)
Return N character
of string S,
beginning from P
Select SUBSTRING(‘LAPTOP’,3,3);
Output – PTO
Select SUBSTR(‘COMPUTER’,4,3);
Output – PUT
UPPER()/
UCASE( )
Return string in
capital letters
Select Upper(‘india’); Output- INDIA
LTRIM( ) Removes leading space Select LTRIM(‘Apple’); Output- ‘Apple’

String Function
TRIM() Remove spaces from
beginning and ending
Select TRIM(‘ Apple ‘); Output-’Apple’
Select * from emp where trim(name) = ‘Suyash’;
INSTR() It search one string in
another string and
returns position, if not
found 0
Select INSTR(‘COMPUTER’,’PUT’); Output-4
Select INSTR(‘PYTHON’,’C++’); Output – 0
LENGTH() Returns number of
character in string
Select length(‘python’); Output- 7
Select name, length(name) from emp
LEFT(S,N) Return N characters of
S from beginning
Select LEFT(‘KV OEF’,2); Output- KV
RIGHT(S,N) Return N characters of
S from ending
Select RIGHT(‘KV OEF’,3); Output- OEF

Numeric Function
MOD(M,N) Return remainder M/N Select MOD(11,5); Output- 1
POWER(B,P) Return B to power P Select POWER(2,5); Output-32
ROUND(N,D) Return number rounded to
D place after decimal
Select ROUND(11.589,2);
Output- 11.59
Select ROUND(12.999,2);
Output- 13.00
SIGN(N) Return -1 for –ve number 1 for
+ve number
Select sign(-10);
Output : -1
Select sign(10);
Output : 1
SQRT(N) Returns square root of N Select SQRT(144); Output: 12
TRUNCATE(
M,N)
Return number upto N place
after decimal without
rounding it
Select Truncate(15.789,2);
Output: 15.79

Date and Time Function
VINOD
KUMAR
VERMA,
PGT(CS),
KV
OEF
KANPUR
&
SACHIN
BHARDWAJ,
PGT(CS),
KV
NO.1
TEZPUR
CURDATE( )/
CURRENT_DATE( )
/ CURRENT_DATE
Return the current date Select curdate(); Select
current_date();
DATE() Return date part from datetime
expression
Select date(‘2018-08-15 12:30’);
Output: 2018-08-15
MONTH() Return month from date Select month(‘2018-08-15’); Output: 08
YEAR() Return year from date Select year(‘2018-08-15’); Output: 2018
DAYNAME() Return weekday name Select dayname(‘2018-12-04’);
Output: Tuesday
DAYOFMONTH() Return value from 1-31 Select dayofmonth(‘2018-08-15’)
Output: 15
DAYOFWEEK() Return weekday index, for
Sunday-1, Monday-2, ..
Select dayofweek(‘2018-12-04’);
Output: 3
DAYOFYEAR() Return value from 1-366 Select dayofyear(‘2018-02-10’)
Output: 41

Date and Time Function
NOW() Return both current date
and time at which the
function executes
Select now();
SYSDATE() Return both current date
and time
Select sysdate()
Difference Between NOW() and SYSDATE() :
NOW() function return the date and time at which function was executed
even if we execute multiple NOW() function with select. whereas SYSDATE()
will always return date and time at which each SYDATE() function started
execution. For example.
mysql> Select now(), sleep(2), now();
Output: 2018-12-04 10:26:20, 0, 2018-12-04 10:26:20
mysql> Select sysdate(), sleep(2), sysdate();
Output: 2018-12-04 10:27:08, 0, 2018-12-04 10:27:10

Class Assignment- PRACTICAL FILE
Write SQL queries for I to vi and outputs for vii to ix.
TABLE: VEHICLE
VCODE VEHICLETYPE PERKM
V01 VOLVO BUS 150
V02 AC DELUXE BUS 125
V03 ORDINARY BUS 80
V05 SUV 30
V04 CAR 18
TABLE: TRAVEL
CNO CNAME TRAVELDATE KM
VCODE NOP
101 K.Niwal 2015-12-13 200
V01 32
103 Fredrick Sym 2016-03-21 120
V03 45
105 Hitesh Jain 2016-04-23 450
V02 42
102 Ravi anish 2016-01-13 80
V02 40
107 John Malina 2015-02-10 65
V04 2

1.To display CNO, CNAME, TRAVELDATE from the table TRAVEL in
descending order of CNO.
2. To display the CNAME in uppercase of all the customers from
the table TRAVEL who are travelling by vehicle with code V01 or
V02.
3.To display the CNO and CNAME , month and Year of TRAVEL for
all those who travelled between ‘2015-12-31’ and ‘2015-05-01’.
4. To add a new column status char(1) to the VEHICLE table.
5. To enter the value as ‘A’ for all Status values.
6. Delete Vehicletype CAR from Vehicle table.
7.SELECT Left(VEHICLETYPE,1) FROM VEHICLE;
8. SELECT A.VCODE,CNAME,VEHICLETYPE FROM TRAVEL A,VEHICLE
B WHERE A.VCODE=B.VCODE AND PERKM<90;
9. SELECT CNAME,KM*PERKM FROM TRAVEL A, VEHICLE B WHERE
A.VCODE=B.VCODE AND A.VCODE=‘V05’;

SQL python for beginners easy explanation with concepts and output .pptx

EXPORTING DATABASE
• Exporting means creating the text file containing all the
database contents which can be imported to any other
computer. We use mysqldump command for this purpose.
To export:
• Open cmd from Start button
Or
• Press Window Key + R and type cmd and press Enter
• Atcmd prompt like C:....> type mysqldump
command

EXPORTING DATABASE
• To export all database
– mysqldump --all-databases > c:mydb.sql
• It will create mydb.sql in C:, we can check it by open it.
• To export single database
– mysqldump myworks > c:mydb2.sql
• To export multiple datbase
– mysqldump myworks company c:mydb3.sql

IMPORTINGDATABASE
• STEP – 1
– Open Notepad and type the following commands

IMPORTING DATABASE
• STEP – 1
– Save this file with mydb.sql or any name, in your
desired location for e.g. C:
• STEP – 2
– Open MySQL and type
• SOURCE C:mydb.sql
– It will create database myworks, 2 tables emp,
students with records. We can check it by “SHOW
TABLES” or “SELECT” command

SQL python for beginners easy explanation with concepts and output .pptx

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