In response to Eus :
> Hi Ho!
>
> Is there a way to check whether or not a subquery returns an empty result set?
You can use EXISTS for that:
-- empty result
test=*# select * from (select 1 where 1=2) foo;
?column?
----------
(0 rows)
-- check if a result exists
test=*# select exists(select * from (select 1 where 1=2) foo);
?column?
----------
f
(1 row)
test=*# select exists(select * from (select 1 where 1=1) foo);
?column?
----------
t
(1 row)
Regards, Andreas
--
Andreas Kretschmer
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