MADE-EASY FULL LENGHT TEST

Question

what would be the output for this query?

inner query returns NULL, right? as S.E > 10 won’t be satisfied. so for every outer tuple of R it shouldn’t produce any result? and so the output should be 0? atleast that’s what i think.

 

but, it says the output is 3(i am assuming number of tuples of R), and i can’t figure out why.

any help would be appreciated! thanks!

Comments

https://gateoverflow.in/369085/Made-easy-full-syllabus-test-1-sql-output

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@palashbehra5got it. thank you!

Answer 1

This question has correlated query.

To solve this question, you need to understand that because S.E>10 is always false, it will return 0. Note- It will return 0 to exist, not empty set. Exist only return false only when empty set is passed to it. So exist condition will be always true and that's because answer will be 3.