SubQuery

hi sir,
What is Correlated and Non-Correlated SubQuery?
I want to know the difference between correlated and non-correlated subquery??

Hi

A correlated subquery is an inner subquery which is referenced by the main outer query such that the inner query is considered as being executed repeatedly.

A noncorrelated subquery is subquery that is independent of the outer query and it can execute on its own without relying on main outer query.

It would be very helpful if you explain me Correlated and Non-Correlated SubQuery with an Example.

It is as simple as this..

For example, consider there are two tables namely student and contact with s and c as alias name respectively in the database named School.

Correlated Subquery:
Select s.student_id, s.student_name
from school.student s
where s.student_id IN
(
select c.student_id
from school.contact c
where MONTH(c.admission) = MONTH(s.admission)
);

Noncorrelated Subquery:
Select s.student_id, s.student_name
from school.student s
where s.student_id IN
(
select c.student_id
from school.contact c
where c.email = ‘heena12(at the rate)abc(dot)com’
);