Question

The UNION SQL clause can be used with _____________

(a) SELECT clause only

(b) DELETE and UPDATE clauses

(c) UPDATE clause only

(d) All of the mentioned

I have been asked this question during an internship interview.

My question is taken from Basic SQL in section Laying the Foundation of SQL Server

Answer 1

The correct option is (a) SELECT clause only

The explanation is: The SQL UNION operator is used to combine the result sets of 2 or more SELECT statements. It removes duplicate rows between the various SELECT statements.