Re: help with aggregation query across a second text array column

Rob Nikander <rob.nikander@gmail.com>

From: Rob Nikander <rob.nikander@gmail.com>
To: Postgres General <pgsql-general@postgresql.org>
Cc: Scot Kreienkamp <Scot.Kreienkamp@la-z-boy.com>
Date: 2018-11-12T15:29:52Z
Lists: pgsql-general

> On Nov 12, 2018, at 9:40 AM, Scot Kreienkamp <Scot.Kreienkamp@la-z-boy.com> wrote:
> …

I’m not too confident in my answer here (there could be a better way), but this might help. You could use the `unnest` function to transform the array into multiple rows. For example, given a table like 

    create table t1 (env text, cls text, cls2 text[]);

I can query it like:

    select env, string_agg(cls, ‘,’)
      from (select env, cls from t1
               union
               select env, unnest(cls2) from t1) t
    group by env;

Rob