SQL Queries & Subqueries MCQs

Question 1

What is a correlated subquery in SQL?

Accepted Answer

A subquery that references a column from the outer query and is re-evaluated for each row of the outer query

Answer

A subquery that runs completely independently of the outer query

Answer

A subquery that can only appear in the SELECT clause

Answer

A subquery that is always faster than a join

Question 2

What is the purpose of the SQL 'ANY' and 'ALL' operators used with a subquery?

Accepted Answer

ANY returns true if the comparison holds for at least one value returned by the subquery, while ALL requires it to hold for every value

Answer

ANY and ALL both mean the exact same thing in SQL

Answer

They are used only to combine two full tables into one

Answer

They can only be used with text columns, never numbers

Question 3

Which SQL operator returns true if a subquery returns at least one row?

Accepted Answer

EXISTS

Answer

IN

Answer

ANY

Answer

HAVING

Core SQL Fundamentals Quiz