Dynamic websites lec3

Dynamic Websites
PHP with Oracle DB By Belal Arfa

Section 3
In this section will discuss
1- Quiz 1 Notes
2- Quiz 2
3- Install Oracle 11g ex
4- SqlDev
5- PL/SQL
6- Stored Procedure
7- Function
8- Triggers
9- HTML

Quiz (2)
Relations:
Classes(class, type, country, numGuns, bore, displacement)
Ships(name, class, launched)
Battles(name, date)
Outcomes(ship, battle, result)

Queries:
a) Find the countries whose ships had the largest number of guns.
b) Find the classes of ships at least one of which was sunk in a battle.
c) Find the names of the ships with a 16-inch bore.
d) Find the battles in which ships of the Kongo class participated.

Quiz (2) Answer
a) SELECT country FROM classes
WHERE numGuns = (SELECT MAX(numGuns) from classes);

b) SELECT DISTINCT class FROM Ships
WHERE name IN (SELECT ship FROM Outcomes WHERE result = ‘sunk’);

c) SELECT name FROM ships
WHERE class IN (SELECT class from classes where bore = 16);
- SELECT name FROM ships, classes
WHERE ships.class = classes.class AND bore = 16;

d) SELECT DISTINCT battle FROM ships, outcomes
WHERE class = ‘Kongo’;

Install Oracle 11g ex
Be aware of OS type, Processor type and Oracle version type.
Download it from Oracle
● Start Setup
● Next.....
● Enter Password be aware of this password
because it will the system password
● Next....
● Install....
● Finish

Sql Developer

How to connect to your Database

PL/SQL
What is PL/SQL?
PL/SQL stands for Procedural Language extension of SQL.
PL/SQL is a combination of SQL along with the procedural features of programming languages.
It was developed by Oracle Corporation in the early 90’s to enhance the capabilities of SQL.
Advantages
● Block Structures: PL SQL consists of blocks of code, which can be nested within each other.
Each block forms a unit of a task or a logical module. PL/SQL Blocks can be stored in the
database and reused.
● Procedural Language Capability: PL SQL consists of procedural language constructs such as
conditional statements (if else statements) and loops like (FOR loops).
● Better Performance: PL SQL engine processes multiple SQL statements simultaneously as a
single block, thereby reducing network traffic.
● Error Handling: PL/SQL handles errors or exceptions effectively during the execution of a
PL/SQL program. Once an exception is caught, specific actions can be taken depending upon
the type of the exception or it can be displayed to the user with a message.

Stored Procedures
A stored procedure is a named PL/SQL block which performs one or more
specific task. This is similar to a procedure in other programming languages.

We can pass parameters to procedures in three ways.
1) IN-parameters
2) OUT-parameters
3) IN OUT-parameters
A procedure may or may not return any value.

Stored Procedure
Syntax
CREATE [OR REPLACE] PROCEDURE proc_name [list of parameters]
IS
Declaration section
BEGIN
Execution section
EXCEPTION
Exception section
END;
IS - marks the beginning of the body of the procedure and is similar to DECLARE in
anonymous PL/SQL Blocks.
The code between IS and BEGIN forms the Declaration section.
The syntax within the brackets [ ] indicate they are optional. By using CREATE OR
REPLACE together the procedure is created if no other procedure with the same name
exists or the existing procedure is replaced with the current code.

Stored Procedure
Example
CREATE OR REPLACE PROCEDURE insertDBUSER
IS
BEGIN
INSERT INTO DBUSER ('USER_ID', 'USERNAME', 'PASSWORD', 'CREATED_DATE')
VALUES (1, 'Belal','123', SYSDATE);
COMMIT;
END;
/
How to execute a Stored Procedure?
There are two ways to execute a procedure.
1) From the SQL prompt: EXECUTE [or EXEC] procedure_name;
2) Within another procedure – simply use the procedure name: procedure_name;
NOTE: In the examples given above, we are using backward slash ‘/’ at the end of the program. This
indicates the oracle engine that the PL/SQL program has ended and it can begin processing the
statements.

Function
What is a Function in PL/SQL?
A function is a named PL/SQL Block which is similar to a procedure. The major difference
between a procedure and a function is, a function must always return a value, but a
procedure may or may not return a value.
Syntax
CREATE [OR REPLACE] FUNCTION function_name [parameters]
RETURN return_datatype;
IS
Declaration_section
BEGIN
Execution_section
Return return_variable;
EXCEPTION
exception section
Return return_variable;
END;

Function
1) Return Type: The header section defines the return type of the function. The return
datatype can be any of the oracle datatypes like varchar, number etc.
2) The execution and exception section both should return a value which is of the data
type defined in the header section.
For example, let’s create a function called ''employer_details_func'
CREATE OR REPLACE FUNCTION employer_details_func
RETURN VARCHAR(20);
IS
emp_name VARCHAR(20);
BEGIN
SELECT first_name INTO emp_name
FROM emp_tbl WHERE empID = '100';
RETURN emp_name;
END;
/

Function
How to execute a PL/SQL Function?
A function can be executed in the following ways.
1) Since a function returns a value we can assign it to a variable.
employee_name := employer_details_func;
If ‘employee_name’ is of datatype varchar we can store the name of the employee
by assigning the return type of the function to it.

2) As a part of a SELECT statement
SELECT employer_details_func FROM dual;

3) In a PL/SQL Statements like,
dbms_output.put_line(employer_details_func);
This line displays the value returned by the function.

Triggers

A trigger is a pl/sql block structure which is fired when a DML
statements like Insert, Delete, Update is executed on a
database table.
A trigger is triggered automatically when an associated DML
statement is executed.

Triggers
Syntax:
CREATE [OR REPLACE ] TRIGGER trigger_name
{BEFORE | AFTER }
{INSERT [OR] | UPDATE [OR] | DELETE}
[OF col_name] ON table_name
[REFERENCING OLD AS old NEW AS new]
[FOR EACH ROW]
WHEN (condition)
BEGIN
--- sql statements
END;

Triggers
● CREATE [OR REPLACE ] TRIGGER trigger_name - This clause
creates a trigger with the given name or overwrites an existing trigger
with the same name.
● {BEFORE | AFTER } - This clause indicates at what time should the
trigger get fired. i.e for example: before or after updating a table.
● {INSERT [OR] | UPDATE [OR] | DELETE} - This clause determines the
triggering event. More than one triggering events can be used together
separated by OR keyword. The trigger gets fired at all the specified
triggering event.
● [OF col_name] - This clause is used with update triggers. This clause
is used when you want to trigger an event only when a specific column
is updated.

Triggers
● [ON table_name] - This clause identifies the name of the table to which
the trigger is associated.
● [REFERENCING OLD AS old NEW AS new] - This clause is used to
reference the old and new values of the data being changed. By
default, you reference the values as :old.column_name or :new.
column_name. The reference names can also be changed from old (or
new) to any other user-defined name. You cannot reference old values
when inserting a record, or new values when deleting a record,
because they do not exist.
● [FOR EACH ROW] - This clause is used to determine whether a trigger
must fire when each row gets affected ( i.e. a Row Level Trigger) or
just once when the entire sql statement is executed(i.e.statement level
Trigger).
● WHEN (condition) - This clause is valid only for row level triggers. The
trigger is fired only for rows that satisfy the condition specified.

Triggers
For Example: The price of a product changes constantly. It is important to maintain the
history of the prices of the products.
We can create a trigger to update the 'product_price_history' table when the price of the
product is updated in the 'product' table.
1) Create the 'product' table and 'product_price_history' table
CREATE TABLE product_price_history
(product_id number(5),
product_name varchar2(32),
supplier_name varchar2(32),
unit_price number(7,2) );
CREATE TABLE product
(product_id number(5),
product_name varchar2(32),
supplier_name varchar2(32),
unit_price number(7,2) );

Triggers
2) Create the price_history_trigger and execute it.
CREATE or REPLACE TRIGGER price_history_trigger
BEFORE UPDATE OF unit_price
ON product
FOR EACH ROW
BEGIN
INSERT INTO product_price_history
VALUES
(:old.product_id,
:old.product_name,
:old.supplier_name,
:old.unit_price);
END;
/

Triggers

3) Lets update the price of a product.
UPDATE PRODUCT SET unit_price = 800 WHERE product_id = 100
Once the above update query is executed, the trigger fires and updates the
'product_price_history' table.

4)If you ROLLBACK the transaction before committing to the database, the data inserted
to the table is also rolled back.

HTML
HTML or Hypertext Markup Language
is the most widely used language on Web.
Technically, HTML is not a programming language, but rather a markup
language.
Before beginning:
it's important that you know Windows. A working knowledge of Windows
makes it much easier to learn HTML.
You should be familiar with:
Basic word processing using any text editor..
Basic understanding on internet browsing using a browser like Google Chrome
or Firefox etc.

HTML
Creating HTML Document:
- Open Notepad or another text editor and type:
<html>
<head>
<title>This is document title</title>
</head>
<body>
<h1>This is a heading</h1>
<p>Document description goes here.....</p>
</body>
</html>
- Name the file template.html.
- Click Save.

HTML
Now you have created one HTML page and you can use a Web Browser to
open this HTML file to see the result.

Hope you understood that Web Pages are nothing but they are simple HTML
files with some content which can be rendered using Web Browsers.

Here <html>, <head>,...<p>, <h1> etc. are called HTML tags.
HTML tags are building blocks of an HTML document.

NOTE: One HTML file can have extension as .htm or .html. So you can use
either of them based on your comfort.

HTML
HTML Document Structure:
An HTML document starts and ends with <html> and >/html> tags. These tags
tell the browser that the entire document is composed in HTML. Inside these
two tags, the document is split into two sections:
The <head>...</head> elements, which contain information about the
document such as title of the document, author of the document etc.
The <body>...</body> elements, which contain the real content of the
document that you see on your screen.
HTML Tags and Elements:
HTML language is a markup language and we use many tags to markup text. You
have seen <html> etc. are called HTML tags or HTML elements.
Every tag consists of a tag name, sometimes followed by an optional list of tag
attributes , all placed between opening and closing brackets (< and >).
According to the HTML standard, tag and attribute names are not case-sensitive.
There's no difference in effect between <HEAD> and <HeaD>;

HTML
HTML Attributes:
An attribute is used to define the characteristics of an element and is placed inside the
element's opening tag.
All attributes are made up of two parts: a name and a value:
The name is the property you want to set.
The value is what you want the value of the property to be.
The value of the attribute should be put in double quotation marks, and is separated from
the name by the equals sign. <font face="arial" color="#CC0000">
The four core attributes that can be used on the majority of HTML elements
(although not all) are:
id
title
class
style
<p style="font-family:arial; color:#FF0000;">Some text...</p>

HTML
Create Headings - The <hn> Elements:
Any documents starts with a heading. You use different sizes for your
headings. HTML also have six levels of headings, which use the elements
<h1>, <h2>, <h3>, <h4>, <h5>, and <h6>. While displaying any heading,
browser adds one line before and after that heading.
Example:
<h1>This is heading 1</h1>

HTML
Line Breaks
Hello<br />
You come most carefully upon your hour.<br />
Thanks<br />
Mahnaz
Center Content
<p>This is not in the center.</p>
<center> <p>This is in the center.</p> </center>
Bold Text
<p>The following word uses a <b>bold</b> typeface.</p>
Italic Text
<p>The following word uses a <i>italicized</i> typeface.</p>

HTML
Style Tag
The HTML <style> tag is used for declaring style sheets within the head of your HTML
document.
<head>
<style type="text/css">
h1 { color:#F1F1F1 }
</style>
</head>

<html>
<body style="background-color:yellow;">
<h2 style="background-color:red;">This is a heading</h2>
<p style="background-color:green;">This is a paragraph.</p>
</body>
</html>

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