Re: Sorting by NULL values

On Tue, 4 Mar 2003, Ian Burrell wrote:

> I am doing a query where I need to sort by a column that may be NULL
> because it is coming from an OUTER JOIN.  I noticed a difference between
> PostgreSQL and other databases about where NULLs show up.  It seems that
> with Postgres, NULLs are sorted after other values.  Other databases
> sort them before.

> Is there any standard on how sorting NULLs work?  Is there a way to

IIRC, they're either considered greater than or less than non-NULL values,
but the decision is up to the implementation.

> change Postgres's behavior?  Is there a way to replace the NULLs with
> empty strings?

Coalesce should work.