Date: Thu, 4 Dec 2025 14:26:03 -0800 (PST)
From: Rich Shepard <rshepard@appl-ecosys.com>
To: "pgsql-general@postgresql.org" <pgsql-general@postgresql.org>
Subject: Re: Extract only maximum date from column
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On Thu, 4 Dec 2025, David G. Johnston wrote:

> As mentioned, the aggregate max should be avoided - you aren’t doing
> statistics, you are ranking.

David,

Got it.

> Select person.*, lastcontact.* from person join lateral (select contact.*
> from contact where contact.person_id=person.person_id order by
> last_contact_date desc limit 1) as lastcontact on true;

Select person.*, lastcontact.*
from people
join lateral (select contact.*
      from contacts
      where contacts.person_nbr = people.person_nbr
      order by last_contact_date
      desc limit 1)
as lastcontact on true;

psql:companies-contacted-2025.sql:10: ERROR:  missing FROM-clause entry for table "contact"
LINE 3: join lateral (select contact.*

So:
Select person.*, lastcontact.*
from people
join lateral (select contacts.*
      from contacts
      where contacts.person_nbr = people.person_nbr
      order by last_contact_date
      desc limit 1)
as lastcontact on true;

psql:companies-contacted-2025.sql:10: ERROR:  column "last_contact_date" does not exist
LINE 6:      order by last_contact_date
                       ^
Regards,

Rich