MY SQL

Eng: SAHAR

Introduction to SQLIntroduction to SQL

What is SQL? When a user wants to get some

information from a database file, he can issue a query

A query is a user–request to retrieve data or information with a certain condition

SQL is a query language that allows user to specify the conditions. (instead of algorithms )

Language SQL

Data Multiplication Language ( DML)

البيانات معالجة لغة

Data Definition Language (DDL)

البيانات تعريف لغة

Data Multiplication Language ( DML)

Select

Insert

Update

Delete

Select StatementSelect Statement

SELECTSELECT Field NameField Name FROM FROMTable NameTable Name

EX: We have This Table With the name EX: We have This Table With the name MyTableMyTable

And we need to select ID FieldAnd we need to select ID Field

ID Name Salary

1 Ali 700

2 Ahmed 800

Solution

Select Id From MyTable

Result:

ID

1

2

EX:EX: We have This Table With the name We have This Table With the name MyTableMyTableAnd we need to select ID ,Name Fields And we need to select ID ,Name Fields

Select Id, Name From MyTable ID Name

1 Ali

2 Ahmed

Result:

To Select all table Fields

Select * From Table Name

We Use * instead of write of all Fields

ID Name Salary

1 Ali 700

2 Ahmed 800

Then If We Apply This For above Example

Solution will be: Select * From MyTable

Where …

If We Have a condition in using Select we can use where

Select Field name From Table Name Where Condition

Where Conditions

= Equal

<> Not Equal

> More Than

< Less Than

>= More Than or equal

<= Less Than or equal

EX: From Above Table Select All data

about Ali

Solution Select * From MyTable Where Name

=“ Ali”

INSERTINSERT StatementStatement

Insert into Insert into Table nameTable name ( (Fields nameFields name) ) Values ( Values ( Field valuesField values))

Ex : Ex : Insert Into MyTable (ID, Name, Address, ID, Name, Address, Note) Values (4,’Kindy’,’Cairo’,’SQL’)Note) Values (4,’Kindy’,’Cairo’,’SQL’)

The Result will be :

ID Name Address Note

1 Ibrahim Cairo VB,MYSQL

2 Basma Geza VB.Net

3 Ola Alex ASP

4 Kindy Cairo SQL

Delete StatementDelete Statement

Delete From Table Name Where Condition

EX: Delete Form MyTable Where Name=‘Kindy’Where Name=‘Kindy’

The Result will be :

ID Name Address Note

1 Ibrahim Cairo VB,MYSQL

2 Yomna Geza VB.Net

3 Ola Alex ASP

UpDateUpDate StatementStatement

UpDate UpDate Table nameTable name Set Set Field Name = Field Name = valuesvalues

Ex : Ex : Up date MyTable set YomnaYomna instead of BasmaBasma

Solution

Update MyTable Set NameName = ‘Yomna’ Where = ‘Yomna’ Where NameName=‘Basma’=‘Basma’

ID Name Address Note

1 Ibrahim Cairo VB,MYSQL

2 Yomna Geza VB.Net

3 Ola Alex ASP

4 Kindy Cairo SQL

Data Definition Language ( DDL)

CREATE

ALTER

DROP

RENAME

Create Statement

Create Table Table Name <Field name> <Field Type >

Field Type …..

Char(X)

VarChar(X)

Integer

Date

EX: Create Table MyTable (ID Integer, Name

Varchar(15),Address Varchar(15),Note Varchar(50))

ID Name Address Note

Alter Statement

Alter Table Table Name Add <Field name> <Field Type >

EX: Alter Table MyTable Add Date

date

ID Name Address

Note Date

Rename Statement

Alter Table Table Name Rename to New Name

EX: Alter Table MyTable Rename To

Sales

Drop Statement

Drop Table Table Name

EX: Drop Table MyTable