Обсуждение: bug in 9.2.2 ? subquery accepts wrong column name : upd

dynacom=# SELECT DISTINCT ON (qry.setid) qry.setid, qry.arragg[1:2] FROM (select distinct
sst.setid,(array_agg(vsl.name)OVER (PARTITION BY sst.setid ORDER BY character_length(vsl.name))) as arragg FROM sissets
sst,vessels vsl WHERE vsl.id=sst.vslid ORDER BY sst.setid) as qry     WHERE array_length(qry.arragg,1)>1  AND qry.setid
IN(SELECT setid from sis_oper_cons) ORDER BY qry.setid,array_length(qry.arragg,1);setid |              arragg
  
 
-------+----------------------------------   54 | {EQUZZZ,SAMZZZ}   55 | {"ZZZR","ZZZTRAVEL"}   81 | {"ZZZ SISTER","ZZZ
DUMMYII"}
 
(3 rows)

however, there is not column setid in sis_oper_cons,

dynacom=# SELECT setid from sis_oper_cons;
ERROR:  column "setid" does not exist
LINE 1: SELECT setid from sis_oper_cons;              ^
9.2.2 Postgresql treats qry.setid IN (SELECT setid from sis_oper_cons) as true.
However, making subquery look like (SELECT soc.setid from sis_oper_cons soc), as in 

dynacom=# SELECT DISTINCT ON (qry.setid) qry.setid, qry.arragg[1:2] FROM (select distinct
sst.setid,(array_agg(vsl.name)OVER (PARTITION BY sst.setid ORDER BY character_length(vsl.name))) as arragg FROM sissets
sst,vessels vsl WHERE vsl.id=sst.vslid ORDER BY sst.setid) as qry WHERE array_length(qry.arragg,1)>1  AND qry.setid NOT
IN(SELECT soc.setid from sis_oper_cons soc) ORDER BY qry.setid,array_length(qry.arragg,1);
 
ERROR:  column soc.setid does not exist
LINE 1: ...gth(qry.arragg,1)>1  AND qry.setid NOT IN (SELECT soc.setid ...
             ^
 
dynacom=# 

postgresql corerctly identifies and throws the error.

-
Achilleas Mantzios
IT DEV
IT DEPT
Dynacom Tankers Mgmt

Achilleas Mantzios <achill@matrix.gatewaynet.com> writes:
> dynacom=# SELECT DISTINCT ON (qry.setid) qry.setid, qry.arragg[1:2] FROM 
>     (select distinct sst.setid,(array_agg(vsl.name) OVER (PARTITION BY sst.setid ORDER BY
character_length(vsl.name)))as arragg 
 
>     FROM sissets sst, vessels vsl WHERE vsl.id=sst.vslid ORDER BY sst.setid) as qry 
>      WHERE array_length(qry.arragg,1)>1  AND qry.setid IN (SELECT setid from sis_oper_cons) ORDER BY
qry.setid,array_length(qry.arragg,1);
> [ works ]

> however, there is not column setid in sis_oper_cons,

If not, that's a perfectly legal outer reference to qry.setid.

Probably not one of SQL's better design features, since it confuses
people regularly; but it's required by spec to work like that.
        regards, tom lane

Thanx Tom.

On Πεμ 14 Μαρ 2013 12:17:46 Tom Lane wrote:
> Achilleas Mantzios <achill@matrix.gatewaynet.com> writes:
> > dynacom=# SELECT DISTINCT ON (qry.setid) qry.setid, qry.arragg[1:2] FROM
> >     (select distinct sst.setid,(array_agg(vsl.name) OVER (PARTITION BY sst.setid ORDER BY
character_length(vsl.name)))as arragg  
> >     FROM sissets sst, vessels vsl WHERE vsl.id=sst.vslid ORDER BY sst.setid) as qry
> >      WHERE array_length(qry.arragg,1)>1  AND qry.setid IN (SELECT setid from sis_oper_cons) ORDER BY
qry.setid,array_length(qry.arragg,1);
> > [ works ]
>
> > however, there is not column setid in sis_oper_cons,
>
> If not, that's a perfectly legal outer reference to qry.setid.
>
> Probably not one of SQL's better design features, since it confuses
> people regularly; but it's required by spec to work like that.
>
>             regards, tom lane
>
>
>
-
Achilleas Mantzios
IT DEV
IT DEPT
Dynacom Tankers Mgmt