The number of columns that can be listed in the GROUP BY clause is an implementation limit of the database server. All database servers support at least eight columns. Review the current statement to ensure that the punctuation of the GROUP BY clause is correct. If it is as you intended, you will have to find a way to make this query in two or more stages. Since you must list all nonaggregate selected columns in the GROUP BY clause, and the length of the list is restricted, you must select only the non-aggregate values that are required to distinguish each group. Put the group results in a temporary table, and join this table to the original table to select other non-aggregate values.