Script for database (Select two table)

Example of database table :
The table name is Names

Code	Name
A01	Leo
A02	Aries
A03	Taurus

Example of database table :
The table name is Values

Code	Value
A01	90
A02	100
A03	95

• Query with two table

SELECT Table_name.Field_name, Table_name.Field_name,....

FROM Table_name, Table_name

WHERE Condition

Example:

SELECT Names.Code, Names.Name, Values.Value

FROM Names, Values

WHERE Names.Code=Values.Code

The display is:

Code	Names	Value
A01	Leo	90
A02	Aries	100
A03	Taurus	95

• Using alias

SELECT Alias1.Field_name, Alias2.Field_name,....

FROM Table_name Alias1, Table_name Alias2

WHERE Condition

Example:

SELECT A.Code, A.Name, B.Value

FROM Names A, Values B

WHERE A.Code=B.Code

The display is:

Code	Names	Value
A01	Leo	90
A02	Aries	100
A03	Taurus	95

• Cartesian (Select all without where)

SELECT *

FROM Table_name, Table_name

Example:

SELECT *

FROM Names, Values

The display is:

Code	Names	Value
A01	Leo	90
A02	Aries	100
A03	Taurus	95

• Equijoin

Equijoin is join table use where. the example is same with the alias example.