Progress
SQL-92
Guide and Reference
EXISTS Predicate
The EXISTS predicate can be used to check for the existence of specific rows. The query_expression returns rows rather than values. The predicate evaluates to true if the number of rows returned by the query_expression is nonzero.
This is the syntax for an exists_predicate:
EXAMPLE
In this example, the predicate evaluates to true if the specified customer has any orders:
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