SQL EXISTS Operator for Beginners

In SQL, the EXISTS operator specifies a subquery to test for the existence of rows. It returns TRUE when the subquery returns one or more rows.

A subquery is a query that is nested inside another query (or even another subquery)

This article contains some basic examples of the EXISTS operator.

SQL IN Operator for Beginners

In SQL, the IN operator allows you to filter your query results based a list of values.

You can also use it to match any value returned by a subquery (a subquery is a query that’s nested inside another query).