Re: Problem with result ordering

Tom Lane wrote:
> Thorsten =?iso-8859-1?q?K=F6rner?= <t.koerner@cappuccinosoft.de> writes:
>
>> select m_id, m_u_id, m_title, m_rating from tablename where m_id in (26250,
>> 11042, 16279, 42197, 672089);
>>
> You could rewrite the query as
>
> select ... from tablename where m_id = 26250
> union all
> select ... from tablename where m_id = 11042
> union all
> select ... from tablename where m_id = 16279
> union all
> select ... from tablename where m_id = 42197
> union all
> select ... from tablename where m_id = 672089
>
> This isn't guaranteed by the SQL spec to produce the results in any
> particular order either; but there's no good reason for PG to rearrange
> the order of the UNION arms, whereas there are plenty of good reasons to
> try to optimize fetching of individual rows.
>


Or a variant of this,
SELECT m_id, m_u_id, m_title, m_rating from tablename where m_id in (26250,
11042, 16279, 42197, 672089) ORDER BY m_id=26250, m_id=11042,
m_id=16279, m_id=42197, m_id=672089;


--
Tommy Gildseth
http://www.gildseth.com/