Hi
2018-05-16 8:14 GMT+02:00 Philipp Kraus <philipp.kr...@tu-clausthal.de>:
> 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?
>
> Thanks
>
maybe you want array_to_string function
postgres=# select array['a','b'];
┌───────┐
│ array │
╞═══════╡
│ {a,b} │
└───────┘
(1 row)
postgres=# select array_to_string(array['a','b'],'');
┌─────────────────┐
│ array_to_string │
╞═════════════════╡
│ ab │
└─────────────────┘
(1 row)
Regards
Pavel
>
> Phil
>
>
>
>
