EXISTS

An EXISTS condition tests for existence of rows in a subquery.

exists_condition::=
Description of exists_condition.gif follows

Table 6-10 shows the EXISTS condition.

Table 6-10 EXISTS Condition

Type of Condition	Operation	Example
EXISTS	`TRUE` if a subquery returns at least one row.	SELECT department_id FROM departments d WHERE EXISTS (SELECT * FROM employees e WHERE d.department_id = e.department_id);