indira
Answered On : Feb 1st, 2012
Sub query: A sub query is executed once for the parent statement.
Correlated Sub query: Correlated sub query runs once for each row selected by the outer query. It contains a reference to a value from the row selected by the outer query.
Example:
Select e1.empname, e1.basicsal, e1.deptno
From emp e1
Where e1.basicsal = (Select max(basicsal) From emp e2 Where e2.deptno = e1.deptno)
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