Re: We are not following the spec for HAVING without GROUP

Christopher Kings-Lynne <chriskl@familyhealth.com.au>

From: Christopher Kings-Lynne <chriskl@familyhealth.com.au>
To: Kevin Brown <kevin@sysexperts.com>
Cc: pgsql-hackers@postgresql.org
Date: 2005-03-10T04:00:26Z
Lists: pgsql-bugs, pgsql-hackers
>>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