Re: Controlling Reuslts with Limit

My understanding:
because you return a subset instead of a single value,
so between 2 select ... limit ... queries.
if you delete a record(say song_id=947) then insert it again.
then results are different.
So for a multiple users db, you should use oder by when you use limit.


Jie LIANG

St. Bernard Software
Internet Products Inc.

10350 Science Center Drive
Suite 100, San Diego, CA 92121
Office:(858)320-4873

jliang@ipinc.com
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On Sat, 24 Feb 2001, Najm Hashmi wrote:

> Hi,
>  I was reading through Bruce's on line . I found follwing bit unclear...
> 
> "Notice that each query uses ORDER BY . Although this clause is not required,
> LIMIT without ORDER BY returns random rows from the query, which would be
> useless. "
> 
> When I run a query several time  I get the same results as given
> flipr=# select song_id from songs  limit 5;
>  song_id
> ---------
>      945
>      946
>      947
>      948
>      949
> (5 rows)
> 
> flipr=# select song_id from songs  limit 5;
>  song_id
> ---------
>      945
>      946
>      947
>      948
>      949
> (5 rows)
> 
> flipr=# select song_id from songs  limit 5;
>  song_id
> ---------
>      945
>      946
>      947
>      948
>      949
> (5 rows)
> 
> flipr=# select song_id from songs  limit 5;
>  song_id
> ---------
>      945
>      946
>      947
>      948
>      949
> (5 rows)
> 
> flipr=# select song_id from songs  limit 5;
>  song_id
> ---------
>      945
>      946
>      947
>      948
>      949
> (5 rows)
> 
> flipr=# select song_id from songs  limit 5;
>  song_id
> ---------
>      945
>      946
>      947
>      948
>      949
>  I just want to know what exatly --"LIMIT without ORDER BY returns random rows
> from the query" --means
> Regards
>