AI-assisted, automatically checked• Updated August 2026

SQL MCQs

SQL multiple choice questions covering SELECT queries, joins, aggregations, subqueries, and indexing.

53 MCQs2 subtopicsProgrammingAll Levels

Key Concept Overview & Exam Context

Review core principles of SQL before answering questions. These questions simulate placement technical assessments (TCS, Infosys, Amazon), university exams (CS/IT), and technical certifications.

Target Readiness

Placements & Job Interviews

Question Format

Multiple-Choice with Explanations

Explained Solutions

Written explanations

Core SQL Fundamentals Quiz

10 questions · Interactive timed test · Instant score & review

Start Quiz

Browse by Subtopic

All TopicsJoins Queries & Subqueries

SQL MCQ Questions

Page 2 of 2 (53 total)

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

medium

View Answer & Explanation

Correct Answer: EXISTS

Explanation:

The EXISTS operator tests for the existence of any record in a subquery and returns true as soon as the first matching row is found.

What is the Cartesian product join of two tables with M and N rows respectively?

medium

View Answer & Explanation

Correct Answer: M * N rows via CROSS JOIN

Explanation:

A CROSS JOIN produces the Cartesian product of two tables, resulting in M * N rows.

Which SQL constraint uniquely identifies each record in a database table and disallows NULL values?

easy

View Answer & Explanation

Correct Answer: PRIMARY KEY

Explanation:

A PRIMARY KEY constraint uniquely identifies each record and strictly forbids NULL values. UNIQUE constraints allow NULL values.

Showing 51 to 53 of 53 questions