what where exists and not exists will do in SELECTstatement?

shivakumar .b · New User Joined: 11 May 2005 Posts: 18 Location: bangalore

hi everybody,
This is shivakumar.
I want to know what the WHERE EXISTS AND WHERE NOT EXISTS will do in SELECT statement, that is i want to know for what purpose we are using this exists clause.
i am waiting for reply.
thanks in advance.

priyesh.agrawal · Posted: Wed May 11, 2005 5:16 pm

Check the link...

ajay_dheepak · New User Joined: 12 May 2005 Posts: 32 Location: Chennai

consider the following query

SELECT EMPNO,LASTNAME
FROM TABLE1
WHERE EXISTS
(SELECT *
FROM TABLE2 WHERE BDATE < '1986-01-01');

The above query returns all the EMPNO and LASTNAME if there is any BDATE in TABLE2 which is less than '1986-01-01'.

shivakumar .b · New User Joined: 11 May 2005 Posts: 18 Location: bangalore

HELLO AJAY_DHEEPAK, THANK U VERY MUCH FOR U R REPLY.
YOU HAVE MENTIONED A VERY GOOD EXAMPLE. THANKS A LOT.
BYE
REGARDS,
B.SHIVAKUMAR