Sounds to me like this: http://joecelkothesqlapprentice.blogspot.nl/2007/12/using-where-clause-parameter.html
> To: pgsql-sql@postgresql.org > From: spam_ea...@gmx.net > Subject: [SQL] Using regexp_matches in the WHERE clause > Date: Mon, 26 Nov 2012 13:13:06 +0100 > > Hi, > > I stumbled over this question on Stackoverflow > > http://stackoverflow.com/questions/13564369/postgresql-using-column-data-as-pattern-for-regexp-match > > And my initial reaction was, that this should be possible using > regexp_matches. > > So I tried: > > SELECT * > FROM some_table > WHERE regexp_matches(somecol, 'foobar') is not null; > > However that resulted in: ERROR: argument of WHERE must not return a set > > Hmm, even though an array is not a set I can partly see what the problem is > (although given the really cool array implementation in PostgreSQL I was a > bit surprised). > > > So I though, if I convert this to an integer, it should work: > > SELECT * > FROM some_table > WHERE array_length(regexp_matches(somecol, 'foobar'), 1) > 0 > > but that still results in the same error. > > But array_length() clearly returns an integer, so why does it still throw > this error? > > > I'm using 9.2.1 > > Regards > Thomas > > > > > -- > Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-sql
