Question

The operators used when a subquery returns multiple rows to be evaluated in comparison to the outer query are _____________

(a) IN and NOT IN

(b) EXISTS and NOT EXISTS

(c) OUTER JOIN and INNER JOIN

(d) LEFT JOIN and RIGHT JOIN

I have been asked this question during an interview for a job.

This question is from Managing MySQL User Accounts in section General MySQL Administration of MySQL

Answer 1

Right option is (a) IN and NOT IN

To explain I would say: When there is a need to evaluate multiple rows in comparison to the outer query, the ‘IN’ and ‘NOT IN’ operators are used. They are used for testing whether a comparison value is present in a set of values.