Thread

1. Re: subselects

   Zeugswetter Andreas <andreas.zeugswetter@telecom.at> — 1998-01-21T08:42:52Z

   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
   
   

2. Re: [HACKERS] Re: subselects

   Bruce Momjian <maillist@candle.pha.pa.us> — 1998-01-21T15:09:37Z

   > 
   > 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
   
   

3. Re: [HACKERS] Re: subselects

   Marc G. Fournier <scrappy@hub.org> — 1998-01-21T15:18:29Z

   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
   
   
   
   

4. Re: [HACKERS] Re: subselects

   Bruce Momjian <maillist@candle.pha.pa.us> — 1998-01-21T16:03:19Z

   > > 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