The document discusses dynamic websites using PHP with an Oracle database. It begins by defining what a relational database is and the advantages of using a database over files, including centralization of data, high performance, reduced data redundancy, better security and integrity. It then discusses database structure, explaining that a database consists of logical tables that contain columns, indexes, foreign keys etc. and that a table stores data in rows and columns. It provides an example table to demonstrate this. It further explains concepts like primary keys, unique constraints, not null constraints and foreign keys and how they maintain data integrity. The document concludes by discussing how to design the database using concepts learned and provides SQL examples to demonstrate creating, reading, updating and deleting data from

1. Dynamic Websites
PHP with Oracle DB By Belal Arfa

2. What is Relational DB?
A Database is a “Special Data Container” in
which the computer stores large
amounts of data.

3. DB VS Files ?
– Total Centralization
( Cinema Tickets )
– Highest Performance Measures
( Deal with large data with no crash ) Don't Worry if you
– Reducing Data Redundancy didn't understand
these terminologies
( PK and FK employees and Depts )
– Better Data Security
– Full Data Integrity
( Foreign Key )

4. DB Structure ?
Database is a group of logical tables
and table includes columns, indexes, foreign
keys, etc...
But what are tables ?
this is a table
Car_Code Car_Name
1001 BMW
1002 MERCEDES
1003 PORSCHE
1004 FIAT

5. Tables
– A Table is composed of Rows (Data in the Table) and
Columns (Table's Structure)...
– A Table is used to Store data in it, in the above it is
storing data about Cars Brands.
– We Can Insert, Update, Delete and Read Table's Data.

6. Tables
So we said that Database is a group of related and
interconnected tables, HOW ???
we can describe a car by Brand and Model...
There is a logical connection between Brands and
Models...
ex.
BMW Brand has many Models ( X3,X6, etc...)
Mercedes Brand has many Models ( CLK, etc...)

7. Tables
Primary Key (Unique and Not Null)
Car_Code Car_Name
1001 BMW
Primary Key (Unique and Not Null)
1002 MERCEDES
1003 PORSCHE
1004 FIAT
Model_Code Brand_Code Model_Name
1 1001 X1
Foreign Key (Referential Integrity) 2 1001 X2
3 1002 C200
4 1004 128

8. Tables
So what are unique and not null ?
Unique
Can we have 2 different brands having the same Code???
Can we give BMW code 10001 and Mercedes the same?
Brand_Code Brand_Name
1001 BMW
1001 MERCEDES
Logically NO !!!
That is what “Unique Constraint” guarantee, when you create one
on a certain column.

9. Tables
Not Null
Can we have Brand Without a Code???
Can we add a new Brand JEEP, and leave it's code
blank??
Brand_Code Brand_Name
.... .....
JEEP
NO!!!
That is what “Not Null Constraint” guarantee for a certain
columns you specify. It arises an error when someone inserts a
Brand without inserting a code for it.

10. Tables
Unique constraint + Not Null Constraint = Primary Key
Column(s) potentially having both constraints are
candidates for us to specify them as the “Primary Key”
of the table. Pk combines both constraints, it uniquely
identifies each Row.

11. Tables
Can we Insert a New Model and assign it to a Non Existent
Brand??
Model_Code Brand_Code Model_Name
1 1001 X!
5 9999 ABC
Also Can we Delete a Model who has Child Brands???
Brand_Code Brand_Name
1001 BMW
..... .....

12. Tables
Certainly NO!!
And This is “Data Integrity”!!!
You Remember the Database Advantages we Mentioned
before???
This is the “Referential Integrity” we gain by adding a
“Foreign Key” constraint on certain Column(s), and
choosing their parents.
FK guarantees child records can't be assigned to non-
existent parents, and parents can't be deleted as long as
they have children.

13. Tables
From the beginning why we made a Code for each Brand??
Also Why we made a Code Column for each Model???
Why don't we depend on NAMES??
First Because we can have the same name for different
Brands/Models.
Ex Fiat produced F128 model, and VOLX produced F128
model...
We have to distinguish between them!!!
Like the ID of a person,
2 people named AbdelRahaman Omar Mohamed but they have
different Ids.Second, using numbers while relating tables
together minimizes “Redundancy”, we just assign the parent's
code to the child records.

14. Designing The Database
Now that we understand Database concepts, Many companies
developed “Relational Database Management System”,
which is the Software platform we are going to implement our
“Schema” on.
Oracle, MySQL and Microsoft SQL Server are such RDBMS...
So to implement the Schema which is the set of table we will
create, we are going to use Oracle Database Engine.
You can Implement the same by using different engines with
very slight difference!!!!
All RDBMS Implement the same functionality with slight
difference in code syntax.

15. Designing The Database
To interact with the DB engine you will write “Structured Query
Language”.
“SQL” is the programming language used to interact with a DB
Engine. With SQL code, we can
Create, Modify (Alter) and Drop the Database Structure (DDL)....
CRUD: Create, Read, Update, Delete Data (DML)...

16. Designing The Database
We will Learn SQL by Example...
You should install Oracle Express Edition..
Also you should open the SQL Developer, create a new
connection with the User-name system and the password you
specified during installation as illustrated.
Host Name refers to the server the Oracle Database Engine is
installed at.
In our case it's localhost (the same computer), else insert the ip
of the server you installed Oracle at.
SID is xe (Express Edition), else if you installed an Oracle
Standard/Enterprise usually it would be orcl.

17. Designing The Database

18. DDL
DDL
Create, Drop and Alter( Modify ) tables.
Before creating a table take care of:
1- Table Name
2- Columns Names
3- Columns Types
4- Which Column will be PK

19. Example
Create Table Persons
(
P_Id number(20),
LastName varchar2(50) NOT NULL,
FirstName varchar2(50),
Address varchar2(50),
CONSTRAINT PERSON_PK PRIMARY KEY (p_id)
)
Drop Table
Drop Table Persons;
Alter Table ( Add Column )
Alter Table Persons Add weight number(20,10);
Remove Column
Alter Table Persons Drop column weight ;

20. DML
DML
CRUD Create, Read, Update and Delete.
● INSERT INTO - Create new data into a database.
● SELECT - Read data from a database.
● UPDATE - Updates data in a database.
● DELETE - Deletes data from a database.

21. Insert Stmt
Syntax
-Insert Into table_name( col1, col2, col3,.... )
values( value1, value2, value3,.... ) .
-Insert Into table_name
values( value1, value2, value3,.... ) -- all column vals is a must
ex:
-insert into persons values(1,'Arfa','Belal','Egypt');
-insert into persons (p_id,lastname)
values(2,'Omar');

22. Select Stmt
Syntax
SELECT [all|distinct] column_name(s) FROM table_name
WHERE search_condition
ex
- Select * from persons;
- Select firstname, lastname from persons;
- Select Distinct address from persons;
- Select * from persons WHERE address='Egypt';
- Select * from persons where weight > 50;

23. Select Stmt
Operators
Operator Description
= Equal
<> Not Equal
> Greater Than
< Less Than
>= Greater Than or Equal
=< Less Than or Equal
LIKE Search for a pattern
BETWEEN Between inclusive range
IN in specific values

24. Select Stmt
Logic Operators ( The AND & OR Operators )
The AND operator displays a record if both the first condition and the
second condition is true.
The OR operator displays a record if either the first condition or the
second condition is true.
ex
- Select * from persons where firstname = 'Belal' and lastname='Arfa';
- Select * from persons where lastname = 'Arfa' or lastname ='Omar';

25. Order By Clause
Syntax
SELECT column_name(s)
FROM table_name
ORDER BY column_name(s) ASC|DESC
ex
Select * from persons ORDER by firstname;

26. Update Stmt
Syntax
UPDATE table_name
SET column1=value, column2=value2,...
WHERE some_column=some_value;
Note: Notice the WHERE clause in the UPDATE syntax. The WHERE clause
specifies which record or records that should be updated. If you omit the
WHERE clause, all records will be updated!
ex
Update persons set lastname = 'Mohamed' where p_id=1;
Update persons set address = 'Cairo'; -- will update all table data

27. Delete Stmt
Syntax
DELETE FROM table_name
WHERE some_column=some_value;
Note: Notice the WHERE clause in the DELETE syntax. The WHERE clause
specifies which record or records that should be deleted. If you omit the
WHERE clause, all records will be deleted!
Delete from persons where p_id=1;
Delete from persons; -- will delete all table data

28. Examples
Schema:
- Departments ( id, name );
- Employees ( id, name, dept );
get each employee name and his corresponding dept.
Sol
Select e.name, d.name
from employees e , departments d
where e.dept = d.pk

29. Examples
Schema:
- Sailors (sid, sname, rating, age)
- Boats (bid, bname, color)
- Reserves (sid, bid, day)
- Find the names of sailors who have reserved boat #103
Sol
SELECT S.sname
FROM Sailors S, Reserves R
WHERE S.sid = R.sid AND R.bid = 103

30. Examples
Schema:
- Sailors (sid, sname, rating, age)
- Boats (bid, bname, color)
- Reserves (sid, bid, day)
- Find the colors of boats reserved by a sailor named rusty
Sol
SELECT B.color
FROM Sailors S, Reserves R, Boats B
WHERE S.sid = R.sid AND R.bid = B.bid
AND S.sname = ‘rusty’

31. Examples
SELECT S.sname, S.age, S.rating
FROM Sailors S
ORDER BY S.age ASC, S.rating DESC
What does this query compute?
Sol
Find the names, ages, and rankings of all
sailors.
Sort the result in increasing order of age.
If there is a tie, sort those tuples in decreasing
order of rating.

32. Examples
Find names of sailors who have reserved a red or a green boat ?
Sol
SELECT S.sname FROM Sailors S, Reserves R, Boats B
WHERE S.sid = R.sid AND R.bid = B.bid
AND (B.color = ‘red’ OR B.color = ‘green’)
Another Sol
SELECT S.sname FROM Sailors S, Reserves R, Boats B
WHERE S.sid = R.sid AND R.bid = B.bid AND B.color = ‘red’
UNION
SELECT S.sname FROM Sailors S, Reserves R, Boats B
WHERE S.sid = R.sid and R.bid = B.bid AND B.color = ‘green’

33. Examples
SELECT S.sname FROM Sailors S
WHERE S.sid IN ( SELECT R.sid FROM Reserves R
WHERE R.bid=103 )
What does this query compute?
Sol
get all sailors who had reserved boat no. 103
To find sailors who have not reserved 103, use NOT IN

34. Examples
- User (uid, username, age, hometown)
- Network (nid, description, networkname)
- Member (uid, nid)
- Friend (uid1, uid2)
Find the names and ages of all users belonging to a network
named ‘Michigan’ in decreasing order of Age
Sol
SELECT U.username, U.age
FROM User U, Network N, Member M
WHERE U.uid = M.uid AND N.nid = M.nid
AND N.networkname = ‘Michigan’
ORDER BY U.age DESC

35. Examples
Find the names of all users who are friends with
the user with uid 456 (omit duplicates)
Sol
SELECT DISTINCT U2.username
FROM User U, Friend F
WHERE F.uid1 = 456 AND F.uid2 = U2.uid

36. Aggregation Functions
Perform calculation on a set of values and return single value.
Syntax
Select Function(column) fromtable
Name Salary
Mohamed 4000
Hassan 3000
Doaa 6000
Ahmed 4000

37. Aggregation Functions
Requirements Select Stmt Result
Average of salary Select AVG(salary) from employees; 4250
Number of Rows Select COUNT(*) from employees; 4
Distinct Salaries Select COUNT(Distinct Salary) from employees; 3
Highest Salary Select MAX(salary) from employees; 6000
Lowest Salary Select MIN(salary) from employees; 3000
Total Salaries Select SUM(salary) from employees; 17000

38. To Do
Search for Agg functions.
Search for Group By clause.
Search for Having clause.

39. Thank You