SQL exists/in clause in QUEL

>   Can anyone suggest a method to emulate the functionality of the SQL
>   "exists" or "in" clause in QUEL?  I'm primarily an SQL user but I also
>   support quite a bit of legacy QUEL code.  This problem has cropped up
>   before and I'm wondering if any QUEL experts out there have an elegant
>   solution.

Have I died and gone to heaven, or did someone ask a QUEL question?
 
>   In SQL, I would write:
> 
>     select t1.col
>     from table1 t1
>     where t1.col not in (select t2.col from table2 t2)

  range of t1 is table1, t2 is table2
  retrieve ( t1.col)
  where any( t2.all by t1.col where t2.col = t1.col ) = 1

>     select t1.col1
>     from table1 t1
>     where not exists (select t2.col from table2 t2
>                              where t2.col = t1.col)

  range of t1 is table1, t2 is table2
  retrieve ( t1.col)
  where any( t2.all by t1.col where t2.col = t1.col ) = 0

There is plenty more where that came from.  If performance is an issue 
you may want to hear about some variants of the above, but this should 
get you started.

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Roy Hann                                   rhann@tnc.com
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11211-76th Avenue,                         CA-World '97 DBA Track Leader
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