Cardinality violations

Cardinality violations occur when a query that should return only a single row returns more than one row to an Embedded SQL™ application.

**Table 6-2: Cardinality violations**
Message	Value	Description
Subquery returned more than 1 value. This is illegal when the subquery follows =, !=, <, <=, >, >=. or when the subquery is used as an expression.	21000	Occurs when: A scalar subquery or a row subquery returns more than one row. A select into parameter_list query in Embedded SQL returns more than one row.