Re: DISTINCT *and* ORDER BY in aggregate functions on expressions(!)

David G. Johnston <david.g.johnston@gmail.com>

From: "David G. Johnston" <david.g.johnston@gmail.com>
To: mirabilos <tg@evolvis.org>
Cc: pgsql-general@lists.postgresql.org
Date: 2023-02-28T00:44:47Z
Lists: pgsql-general
On Mon, Feb 27, 2023 at 5:22 PM David G. Johnston <
david.g.johnston@gmail.com> wrote:

>
> Lastly, if you do need to care about normalizing the output of JSON you
> should consider writing a function that takes arbitrary json input and
> reformats it, rather than trying to build up json from scratch where every
> individual component needs to be aware and take action.  i.e., get rid of
> the ORDER BY also.  Maybe this belongs in an application layer with tooling
> that already provides this capability.
>
>
Just to clarify/correct myself - if building up json arrays you'll just
remove the distinct and then do a normal aggregate order by based upon
whatever ordering the base data presents.  I was thinking you were doing
order by to get keys in order (i.e., jsonb_object_agg) but that isn't the
case here.

David J.