SQL Reference

EXISTS Predicate

>>-EXISTS--(fullselect)----------------------------------------><
 

The EXISTS predicate tests for the existence of certain rows.

The fullselect may specify any number of columns, and

• The result is true only if the number of rows specified by the fullselect is not zero.
• The result is false only if the number of rows specified is zero
• The result cannot be unknown.

Example:

EXISTS (SELECT * FROM TEMPL WHERE SALARY < 10000)