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

Wed, 21 Jan 1998 09:42:52 +0100
Zeugswetter Andreas DBT <Andreas.Zeugswetter@telecom.at>
Re: subselects
> 
> 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

Wed, 21 Jan 1998 10:09:37 -0500 (EST)
Bruce Momjian <maillist@candle.pha.pa.us>
Re: [HACKERS] Re: subselects
On Wed, 21 Jan 1998, Bruce Momjian wrote:

> > 
> > 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.

	If its easy to add in the next couple of days, sure, go for
it...but can someone explain to me *why* you would use a subselect in the
target list?  I've actually never seen that before :9



Wed, 21 Jan 1998 10:18:29 -0500 (EST)
The Hermit Hacker <scrappy@hub.org>
Re: [HACKERS] Re: subselects
> > 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.
> 
> 	If its easy to add in the next couple of days, sure, go for
> it...but can someone explain to me *why* you would use a subselect in the
> target list?  I've actually never seen that before :9

I have no idea why someone would want to do that.  I have enough trouble
figuring out how the engine is going to execute normal queries, let
alone strange ones like that.

-- 
Bruce Momjian
maillist@candle.pha.pa.us

Wed, 21 Jan 1998 11:03:19 -0500 (EST)
Bruce Momjian <maillist@candle.pha.pa.us>
Re: [HACKERS] Re: subselects