ora.nachs

 Profile Answers by ora.nachs 

• Mar 14th, 2007

 

Self Join is nothing but a table joining with itself.

If the data present inside the same table we need to take a alias of same table.

for ex:
empno   ename   mgr
   1             a        
   2             b          1

here, for the employee 2 , employee 1 is the manager.
To fetch the employee name and his manager name we need to join the table to itself.

Guest

• Mar 27th, 2007

 

Self Join is nothing but a table joining with itself.

It is very helpful to fetching duplicate data from a table..
if we want to fetch the emp_id from emp whice are duplicate in emp tab.
examp:

select a.emp_id ,b.emp_id
    from emp a,emp b
where a.emp_id=b.emp_id and
            a.rowid<>b.rowid.

we can get duplicate value easily by help of self join.
Try it...........

krishnaindia2007

 Profile Answers by krishnaindia2007 

• Jun 22nd, 2008

 

Join the table to itself is called self join. It is used when you need to join the data with the same table data.

Ex:- SELECT A.ENAME,A.SAL ,B.ENAME,B.SAL
       FROM EMP A,EMP B

      WHERE A.MGR = B.EMPNO

vishnu vardhan reddy

 Profile Answers by vishnu vardhan reddy 

• Sep 16th, 2008

 

To join a table itself is called self join.