16.20 - Usage Notes - Teradata Database

Teradata Vantageā„¢ - SQL Functions, Expressions, and Predicates

prodname
Advanced SQL Engine
Teradata Database
vrm_release
16.20
created_date
March 2019
category
Programming Reference
featnum
B035-1145-162K

The function of the EXISTS predicate is to test the result of subquery.

If execution of the subquery returns response rows then the where condition is considered satisfied.

Note that use of the NOT qualifier for the EXISTS predicate reverses the sense of the test. Execution of the subquery does not, in fact, return any response rows. Instead, it returns a boolean result to indicate whether responses would or would not have been returned had they been requested.