SQLINsubquerytutorial

What is IN with a subquery in SQL? Membership check for beginners

IN with a subquery filters "rows where a column's value appears in another query's result". Plain words: filtering by a dynamic list, the difference from a literal list, the NOT IN-with-NULL trap, and comparison with EXISTS. With tables and common pitfalls.

1 min readSQL · IN · subquery · tutorial

IN is a membership check: a value must appear in a list. With a subquery, the list is computed by another SELECT — flexible and required for many real tasks.

This article is currently in Russian. The full English translation is on the way.

Practice on real tasks

Solve tasks in the SQL trainer with instant grading and hints.

Open trainer