On Sat, Feb 19, 2005 at 18:04:32 +0100,
charlie clark <charlie@xxxxxxxxxxxxxx> wrote:
> Dear list,
>
> is there a simple way to change the way ORDER BY works on columns with
> NULLs? I can understand the need for default behaviour but there must be
> cases when this is undesirable. I have such a query with the NULLs arising
> as the result of an OUTER JOIN and I would like to ORDER BY DESC with
> NULLs treated as <= 0. I've already tried a few things but nothing's
> working so far.
Presumably what you mean is that you want NULLs to be output last when
doing a descending order by.
You can do this using ORDER BY whatever IS NULL ASC, whatever DESC .
If you really mean you want to treat them as less than or equal to
0, then you can pick such a value and use coalesce to change NULLs
to that value in the ORDER BY clause.
---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match
