Chapter 18

Subquery Predicates

Abstract

Most programming languages use simple scalar predicates with theta operators. They apply to a single scalar value. SQL also has them, but it also has set-oriented predicates. Since SQL is a set-oriented language this is should not be a surprise. These predicates apply to subsets that are built with subqueries.

Keywords

UNIQUE()

[NOT] EXISTS

[NOT] IN()

< theta > ANY < subquery >

< theta > ALL < subquery >

Most programming languages use simple scalar predicates with theta operators. They apply to a single scalar value. SQL also has them, but it also has set-oriented predicates. Since SQL is a set-oriented language this is should not be a surprise. These predicates apply to subsets that are built with ...

Get Joe Celko's SQL for Smarties, 5th Edition now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.