-112 THE OPERAND OF AN AGGREGATE FUNCTION INCLUDES AN AGGREGATE FUNCTION, AN OLAP SPECIFICATION, OR A SCALAR FULLSELECT

Explanation
 The operand of an aggregate function can be either
an expression or DISTINCT followed by an expression. The operand cannot
be another aggregate function, an OLAP specification, or a scalar
fullselect.

System action
 The statement cannot be processed.

Programmer response
 Correct the use of the aggregate function
to eliminate the invalid expression and reissue the statement.

SQLSTATE
 42607