> Bruce Momjian <maillist@candle.pha.pa.us> writes:
> >> Given
> >> create table t1 (name text, value float8);
> >> 
> >> this fails:
> >> SELECT name, value FROM t1 as touter WHERE
> >> (value/(SELECT AVG(value) FROM t1 WHERE name = touter.name)) > 0.75;
> >> ERROR:  parser: '/' must return 'bool' to be used with subquery
> 
> > Aren't you really saying WHERE col / (subselect).  That doesn't return
> > bool, so the message seems correct.
> 
> No, look again: the result of the subselect is being used as an operand
> within the WHERE clause:
> 	WHERE (value/(SUBSELECT)) > 0.75;
> 
> If the / were the toplevel operator in the WHERE then the message would
> make sense, because the WHERE clause as a whole must yield boolean.
> But that doesn't mean that the operator immediately above the subselect
> must yield boolean.
> 
> Besides, I already fixed this ;-)
> 
> > We don't allow subselects in target lists, or inside expressions.
> 
> We don't allow 'em in target lists, I think (anyone understand why not?)
> but they work fine inside expressions in WHERE or HAVING.

Gee, I didn't know they worked inside an expression, but now looking
at the grammar, I remember seeing that they should.

Added to TODO list.

-- 
  Bruce Momjian                        |  http://www.op.net/~candle
  maillist@candle.pha.pa.us            |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Mon, 10 May 1999 15:07:51 -0400 (EDT)
Bruce Momjian <maillist@candle.pha.pa.us>
subselects
Bruce Momjian <maillist@candle.pha.pa.us> writes:
>> If the / were the toplevel operator in the WHERE then the message would
>> make sense, because the WHERE clause as a whole must yield boolean.
>> But that doesn't mean that the operator immediately above the subselect
>> must yield boolean.
>> 
>> Besides, I already fixed this ;-)
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

> Added to TODO list.

Added what to the TODO list?  The particular behavior complained of
is history...

			regards, tom lane

Mon, 10 May 1999 15:52:04 -0400
Tom Lane <tgl@sss.pgh.pa.us>
Re: subselects 
> Bruce Momjian <maillist@candle.pha.pa.us> writes:
> >> If the / were the toplevel operator in the WHERE then the message would
> >> make sense, because the WHERE clause as a whole must yield boolean.
> >> But that doesn't mean that the operator immediately above the subselect
> >> must yield boolean.
> >> 
> >> Besides, I already fixed this ;-)
>    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> > Added to TODO list.
> 
> Added what to the TODO list?  The particular behavior complained of
> is history...

Oh, I thought you had already fixed this long ago, but it was now being
reported as broken.  Removed from list.

-- 
  Bruce Momjian                        |  http://www.op.net/~candle
  maillist@candle.pha.pa.us            |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Mon, 10 May 1999 16:30:18 -0400 (EDT)
Bruce Momjian <maillist@candle.pha.pa.us>
Re: subselects