>>Comments? Can anyone confirm whether DB2 or other databases allow
>>ungrouped column references with HAVING?
>
> Oracle does not allow such references. It issues "ORA-00979: not a
> GROUP BY expression" when you try to hand it such a reference.
>
> MS SQL Server does not allow such references either, yielding
> "columnname is invalid in the HAVING clause because it is not
> contained in either an aggregate function or the GROUP BY clause.".
>
> Can't comment about DB2.
MySQL allows it:
mysql> create table tab (col integer);
Query OK, 0 rows affected (0.01 sec)
mysql> select col from tab having 2 > 1;
Empty set (0.00 sec)
mysql> insert into tab values (1);
Query OK, 1 row affected (0.00 sec)
mysql> select col from tab having 2 > 1;
+------+
| col |
+------+
| 1 |
+------+
1 row in set (0.00 sec)
Of course, that's not saying much!
Chris