Обсуждение: Alias-Error

Hi,

I am running a query with alias (a self join) against
version 7.3.4 on Suse Linux 7.3 and on FreeBSD (v5?).
It runs fine on Linux, but produces an error on
FreeBSD: "unknown alias C2". And btw: the query runs
on every other DB I have tried...

The Query is something like this:

SELECT DISTINCT C2.cmc_mchap, C2.cmc_sort
    FROM sis_cmca, sis_cmca C2
    WHERE cm_status != 'U' AND sis_cmca.cmc_name='INTERN2000' AND
          C2.cmc_name='INTERN2000' AND sis_cmca.cmc_mchap=C2.cmc_mchap
          ....

What causes this error? Workarounds?

Jost

Jost Richstein <jrichstein@softdecc.com> writes:
> I am running a query with alias (a self join) against
> version 7.3.4 on Suse Linux 7.3 and on FreeBSD (v5?).
> It runs fine on Linux, but produces an error on
> FreeBSD: "unknown alias C2".

The string "unknown alias" appears nowhere in the 7.3 sources.
Are you sure you are talking to a Postgres database?

            regards, tom lane

Ok. The exact error message is as follows:

SQLException Time      : Mon Oct 20 13:15:25 CEST 2003
SQLException ErrorCode : 0
SQLException SQLState  : null
SQLException Message   : ERROR:  Relation "c2" does not exist
SQLException Connection: 4878867

The query is something like this:

SELECT DISTINCT C2.cmc_mchap, C2.cmc_sort
    FROM sis_cmca, sis_cmca C2
    WHERE cm_status != 'U' AND sis_cmca.cmc_name='INTERN2000' AND
          C2.cmc_name='INTERN2000' AND sis_cmca.cmc_mchap=C2.cmc_mchap

Tom Lane wrote:
>
> Jost Richstein <jrichstein@softdecc.com> writes:
> > I am running a query with alias (a self join) against
> > version 7.3.4 on Suse Linux 7.3 and on FreeBSD (v5?).
> > It runs fine on Linux, but produces an error on
> > FreeBSD: "unknown alias C2".
>
> The string "unknown alias" appears nowhere in the 7.3 sources.
> Are you sure you are talking to a Postgres database?
>
>                         regards, tom lane

On Tuesday 21 October 2003 08:17, Jost Richstein wrote:
> Ok. The exact error message is as follows:
>
> SQLException Time      : Mon Oct 20 13:15:25 CEST 2003
> SQLException ErrorCode : 0
> SQLException SQLState  : null
> SQLException Message   : ERROR:  Relation "c2" does not exist
> SQLException Connection: 4878867
>
> The query is something like this:
>
> SELECT DISTINCT C2.cmc_mchap, C2.cmc_sort
>     FROM sis_cmca, sis_cmca C2
>     WHERE cm_status != 'U' AND sis_cmca.cmc_name='INTERN2000' AND
            ^^^^^^^^^
You're missing a table name here. It could be PG is reporting the wrong error.

>           C2.cmc_name='INTERN2000' AND sis_cmca.cmc_mchap=C2.cmc_mchap

--
  Richard Huxton
  Archonet Ltd

You have the alias in upper case: "C2", and postgres complains about a
lower case "c2". May be this some case sensitivity problem ?
Just a thought.

HTH,
Csaba.


On Tue, 2003-10-21 at 09:17, Jost Richstein wrote:
> Ok. The exact error message is as follows:
>
> SQLException Time      : Mon Oct 20 13:15:25 CEST 2003
> SQLException ErrorCode : 0
> SQLException SQLState  : null
> SQLException Message   : ERROR:  Relation "c2" does not exist
> SQLException Connection: 4878867
>
> The query is something like this:
>
> SELECT DISTINCT C2.cmc_mchap, C2.cmc_sort
>     FROM sis_cmca, sis_cmca C2
>     WHERE cm_status != 'U' AND sis_cmca.cmc_name='INTERN2000' AND
>           C2.cmc_name='INTERN2000' AND sis_cmca.cmc_mchap=C2.cmc_mchap
>
> Tom Lane wrote:
> >
> > Jost Richstein <jrichstein@softdecc.com> writes:
> > > I am running a query with alias (a self join) against
> > > version 7.3.4 on Suse Linux 7.3 and on FreeBSD (v5?).
> > > It runs fine on Linux, but produces an error on
> > > FreeBSD: "unknown alias C2".
> >
> > The string "unknown alias" appears nowhere in the 7.3 sources.
> > Are you sure you are talking to a Postgres database?
> >
> >                         regards, tom lane
>
>
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