Friday, October 17, 2008

Joins in Sql Server

Joins in Sql Server:

Joins actualy Performs Two or more Tables combined into a single result set.
Joins can also fetch with different dataBase,different Server also.

There are 5 types of joins available in sql server

1) inner join
2) outer join( left outer join,Right outer join)
3) Full Join
4) Cross Join
5) Self Join

1) inner Join : Two tables having the common column values go with inner join.

select * from emp inner join empsalary

2) outer join:
Outer join has two sub types left outer join,Right outer join
Left outer join: Taking Left side values of the table checking into right side
select * from emp left outer join empsalary
on emp.empid=empsalary.empid
Right Outer join:Taking Right side values of the table checking left side
select * from emp right outer join empsalary
on emp.empid=empsalary.empid

3) Full join :
Full join is combined with left outer join ,Right outer join.
select * from emp full join employee
on emp.empid=employee.empid

4) cross Join: cross join is an carteasion product ,its like matrix format here it wont come on condidtion

select * from emp cross join employee

Self join :

Self join can check within the table called self join.

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