Re: CONCAT returns null

Hello again

> -----Original Message-----
> From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org] On Behalf Of Charles
> Clavadetscher
> Sent: Sonntag, 28. Februar 2016 11:24
> To: 'Sterpu Victor' <victor@caido.ro>; 'PostgreSQL General' <pgsql-general@postgresql.org>
> Subject: Re: [GENERAL] CONCAT returns null
>
> Hello
>
> Just a short question to that.
>
> > CONCAT(f.nrfo, '/', TO_CHAR(fd1.validfrom, 'YYYY-MM-DD'), f2.nrfo, TO_CHAR(fd7.validfrom, 'YYYY-MM-DD'),
> > DATE(fd5.validto)-DATE(fd1.validfrom))
> > that works fine but when I change to this(I added a ' with '):
> > ARRAY_AGG(CONCAT(f.nrfo, '/', TO_CHAR(fd1.validfrom, 'YYYY-MM-DD'), ' with ', f2.nrfo, TO_CHAR(fd7.validfrom,
> 'YYYY-
> > MM-DD'), DATE(fd5.validto)-DATE(fd1.validfrom))) AS temp,
> > then concat returns NULL.
> > Why? I tried to add ' with '::VARCHAR and ' with '::TEXT but the result is still NULL.
>
> Do you get NULL also if you run the query without the call to array_agg(), i.e. for all entries in your table?

Forget it. Should not depend on that. If you have any null entry it will be added in the array as NULL.
Bye
Charles