nandlalseth

 Profile Answers by nandlalseth 

• Aug 14th, 2008

 

Correlated Sub Query:
Select * from emp e where exists (select 1 from dept d where d.deptno = e.deptno)

Nested Sub Query:
Select * from emp e where deptno in (select deptno from dept d)

Pallavi g rao

 Profile Answers by Pallavi g rao 

• Apr 21st, 2011

 

correlated:- outer query is executed first and result is sent to inner query for execution

       select * from emp e1 where e1.basicsal=(selcte max(basicsal) from emp e2 where e2.deptno=e1.deptno)

nested:- inner query is excuted first and result is sent to outer query for execution

       select * from emp where (deptno,basicsal) in (select deptno,max(basicsal) from emp group by deptno)