On Wed, May 16, 2018 at 8:14 AM, Philipp Kraus < philipp.kr...@tu-clausthal.de> wrote:
> Hello, > > I have got a function with a reg expr to split chemical formulas e.g. H2O > -> H2 O. > > CREATE OR REPLACE FUNCTION daimon.text2sumformula(text) RETURNS text[] AS > $$ > select array_agg(i::text) as e from ( select unnest( regexp_matches( > $1, '[0-9]*[A-Z][a-z]?\d*|\((?:[^()]*(?:\(.*\))?[^()]*)+\)\d+', 'g') ) ) > i; > $$ LANGUAGE SQL IMMUTABLE; > > For H2O I get an array with {(H2),(O)} > How I can return the inner elements as text, I would like to get {H2,O} > without round brackets? > like this? postgres=# select array_agg(i[1]) as e from regexp_matches( 'H2O', '[0-9]*[A-Z][a-z]?\d*|\((?:[^()]*(?:\(.*\))?[^()]*)+\)\d+', 'g') t(i); e -------- {H2,O} (1 row)