Обсуждение: Re: [GENERAL] Issue with adding ORDER BY to EXCEPT.

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Re: [GENERAL] Issue with adding ORDER BY to EXCEPT.

От
Jaime Casanova
Дата:
> SELECT encounter.encounter_id, encounter_d.encounter_d_id
> FROM encounter
> JOIN encounter_d on encounter_d.encounter_id = encounter.encounter_id
> EXCEPT
> SELECT encounter.encounter_id, encounter_d.encounter_d_id
> FROM encounter
> JOIN encounter_d on  encounter_d.encounter_id = encounter.encounter_id
> JOIN p_l_d ON p_l_d.patient_id = encounter.patient_mpi
> WHERE encounter_d.encounter_id = encounter.encounter_id
>   AND ((p_l_d.start_date <= encounter_d.from_date OR p_l_d.start_date IS
> NULL)
>    AND (p_l_d.end_date >= encounter_d.from_date OR p_l_d.end_date IS NULL))
> ORDER BY encounter.encounter_id, encounter_d.encounter_d_id

>
> With the ORDER BY
> NOTICE:  adding missing FROM-clause entry for table "encounter"
> NOTICE:  adding missing FROM-clause entry for table "encounter_d"
> ERROR:  ORDER BY on a UNION/INTERSECT/EXCEPT result must be on one of the
> result columns
>
I suppose this is because the columns in the except are the same that
the ones in the main select and the order by get confused.

i'm redirecting to hackers to know if this is a known bug or there is
something wrong in the select? i don't see anything wrong!!

--
regards,
Jaime Casanova
(DBA: DataBase Aniquilator ;)

Re: [GENERAL] Issue with adding ORDER BY to EXCEPT.

От
Martijn van Oosterhout
Дата:
On Tue, Jun 07, 2005 at 12:42:47PM -0500, Scott Marlowe wrote:
> On Tue, 2005-06-07 at 12:16, Jaime Casanova wrote:
> > I suppose this is because the columns in the except are the same that
> > the ones in the main select and the order by get confused.
> >
> > i'm redirecting to hackers to know if this is a known bug or there is
> > something wrong in the select? i don't see anything wrong!!
>
> No, it's because to the order by, the column names are the ones given by
> the part after the period of the first select.  If you do a plain select
> UNION select with no order by, you'll see the title for the columns is
> taken from the first select list column names.
>
> So, the order by needs to be "order by encounter_id, encounter_d_id

Or even easier:

order by 1, 2;

Then you don't even need to know the column names...
--
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.

Re: [GENERAL] Issue with adding ORDER BY to EXCEPT.

От
Scott Marlowe
Дата:
On Tue, 2005-06-07 at 12:16, Jaime Casanova wrote:
> > SELECT encounter.encounter_id, encounter_d.encounter_d_id
> > FROM encounter
> > JOIN encounter_d on encounter_d.encounter_id = encounter.encounter_id
> > EXCEPT
> > SELECT encounter.encounter_id, encounter_d.encounter_d_id
> > FROM encounter
> > JOIN encounter_d on  encounter_d.encounter_id = encounter.encounter_id
> > JOIN p_l_d ON p_l_d.patient_id = encounter.patient_mpi
> > WHERE encounter_d.encounter_id = encounter.encounter_id
> >   AND ((p_l_d.start_date <= encounter_d.from_date OR p_l_d.start_date IS
> > NULL)
> >    AND (p_l_d.end_date >= encounter_d.from_date OR p_l_d.end_date IS NULL))
> > ORDER BY encounter.encounter_id, encounter_d.encounter_d_id
>
> >
> > With the ORDER BY
> > NOTICE:  adding missing FROM-clause entry for table "encounter"
> > NOTICE:  adding missing FROM-clause entry for table "encounter_d"
> > ERROR:  ORDER BY on a UNION/INTERSECT/EXCEPT result must be on one of the
> > result columns
> >
> I suppose this is because the columns in the except are the same that
> the ones in the main select and the order by get confused.
>
> i'm redirecting to hackers to know if this is a known bug or there is
> something wrong in the select? i don't see anything wrong!!

No, it's because to the order by, the column names are the ones given by
the part after the period of the first select.  If you do a plain select
UNION select with no order by, you'll see the title for the columns is
taken from the first select list column names.

So, the order by needs to be "order by encounter_id, encounter_d_id