## -8017: Column must be group column

### Explanation:

A column which is not a group column, i.e., which is not contained in the GROUP clause, was specified in a selected column or in the HAVING clause. Columns that are not group columns can only occur in arguments of the AVG, COUNT, MAX, MIN, STDDEV, SUM and VARIANCE set functions.

### User Action:

Insert the specified column into the group clause as a further group column, or remove it from the selected column or HAVING clause.