Tom Lane wrote:
> Craig Ringer <craig@postnewspapers.com.au> writes:
>> The following query should return 2 records, but returns zero instead:
>
>> test=> select x, regexp_matches(x::text, 'm')
>> test-> FROM generate_series(1,2) AS x;
>> x | regexp_matches
>> ---+----------------
>> (0 rows)
>
> No, that's correct. The SRF returns an empty set, so there are no
> output records. The behavior you seem to be imagining would make it
> impossible to distinguish empty set from a single row containing NULL.
Aah, that makes sense. For some reason I'd been thinking of
regexp_matches as returning a single array, rather than returning a set
of scalar values. RTFM (better) I guess. Sorry.
Thanks for taking a look, it's appreciated.
--
Craig Ringer