Re: sql exist

>Can someone give me an overview of the "exist" function in SQL? Thanks.

Some example might help you. "where exists" yields true if the subselect returns one or more rows. Even if the row is only a null:

select all employees that actually got some money (join would do as well here...)

    select emp.name
    from employee emp
    where exists

        ( select 'X' -- any real column or dummy here. NULL would do as well!

          from salary sal
          where sal.id = emp.id
        );

Arjan. Received on Thu Aug 27 1998 - 20:38:18 CEST