GATE 2012 CS (CS1) – Question 25

Databases · Relational Model: Relational Algebra, Tuple Calculus, SQL · 1 mark · Multiple choice

Which SQL assertions are true? P: HAVING can occur without GROUP BY. Q: HAVING requires GROUP BY. R: Every GROUP BY attribute must appear in SELECT. S: GROUP BY attributes need not all appear in SELECT.

P and R
P and S
Q and R
Q and S

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Show answer and explanation

Correct answer: (C) Q and R

Explanation

The official key is C (Q and R), retained for historical grading. Under standard SQL, HAVING can apply to a single implicit group without an explicit GROUP BY, so P is true and Q false. Grouping columns need not all be projected, so S is true and R false. Thus B is the general SQL answer; the official C conflicts with those semantics.

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