Re: [HACKERS] Re: subselects
Bruce Momjian <maillist@candle.pha.pa.us>
From: Bruce Momjian <maillist@candle.pha.pa.us>
To: Andreas.Zeugswetter@telecom.at (Zeugswetter Andreas DBT)
Cc: pgsql-hackers@hub.org
Date: 1998-01-21T15:09:37Z
Lists: pgsql-hackers
> > Bruce wrote: > > I have completed adding Var.varlevelsup, and have added code to the > > parser to properly set the field. It will allow correlated references > > in the WHERE clause, but not in the target list. > > select i2.ip1, i1.ip4 from nameip i1 where ip1 = (select ip1 from nameip > i2); > 522: Table (i2) not selected in query. > select i1.ip4 from nameip i1 where ip1 = (select i1.ip1 from nameip i2); > 284: A subquery has returned not exactly one row. > select i1.ip4 from nameip i1 where ip1 = (select i1.ip1 from nameip i2 > where name='zeus'); > 2 row(s) retrieved. > > Informix allows correlated references in the target list. It also allows > subselects in the target list as in: > select i1.ip4, (select i1.ip1 from nameip i2) from nameip i1; > 284: A subquery has returned not exactly one row. > select i1.ip4, (select i1.ip1 from nameip i2 where name='zeus') from > nameip i1; > 2 row(s) retrieved. > > Is this what you were looking for ? > > Andreas > > Yes, I know other engines support subqueries and references in the target list. I want to know if we are going to do that for 6.3. Personally, I have never seen much use for it. -- Bruce Momjian maillist@candle.pha.pa.us