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what is different between inline query,subquery& corelated
query?
Answer Posted / ramesh reddy veerabhadra
Subquery is the query in the main select query which runs separately and feeds its output to main query for execution. It runs only once.
SELECT ename, deptno
FROM emp
WHERE deptno = (SELECT deptno
FROM emp
WHERE ename = 'KING');
Corelated sub query uses the values from the main query and runs everytime the main query executes i.e. its simultaneous process.
SELECT ename, deptno, sal
FROM emp x
WHERE sal > (SELECT AVG(sal)
FROM emp
WHERE emp.deptno = x.deptno)
ORDER BY deptno;
| Is This Answer Correct ? | 19 Yes | 6 No |
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