Call this member function to set the parameter to a Null value.
void SetParamValueNull( int nIndex ); void SetParamValueNull( LPCTSTR lpszName );
The index of the field in the recordset, for lookup by zero-based index.
The name of the field in the recordset, for lookup by name.
C++ NULL is not the same as Null, which, in database terminology, means "having no value."