-120   AN AGGREGATE FUNCTION OR OLAP SPECIFICATION IS NOT VALID IN THE CONTEXT IN WHICH IT WAS INVOKED

An aggregate function, a user-defined function that is sourced on an aggregate function, or an OLAP specification is not permitted in the following contexts:

• In a SET clause.
• In a VALUES clause.
• In a SET transition-variable statement.
• In an assignment statement.
• In the key-expression of an index definition.
• In the expression of a RETURN statement.

An aggregate function or an OLAP specification can only be specified in a WHERE clause if the WHERE clause appears within a subquery of a HAVING clause.