Date: Thu, 4 Dec 2025 14:17:45 -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
In-Reply-To: <722e065d-8c21-4012-9752-b43658a99c9c@aklaver.com>
Message-ID: <d28add7e-d21c-4355-e074-2152b7ac5562@appl-ecosys.com>
References: <db81f086-e1a5-5798-f9bd-5bed5b1bc7f4@appl-ecosys.com> <CAKFQuwZEWkgQeWSB7nqzBjHS8kP7kvouT6jhKvfe_G2e3cJvOQ@mail.gmail.com> <54638724-615f-52f-29a6-74e2567b9599@appl-ecosys.com> <722e065d-8c21-4012-9752-b43658a99c9c@aklaver.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII; format=flowed
Archived-At: <https://www.postgresql.org/message-id/d28add7e-d21c-4355-e074-2152b7ac5562%40appl-ecosys.com>
Precedence: bulk

On Thu, 4 Dec 2025, Adrian Klaver wrote:

> Would the below work?:
>
> WITH lc AS (SELECT person_nbr, max(next_contact) AS last_contact from 
> contacts where next_contact > '2025-11-01' group by c.person_nbr)
> select p.person_nbr, p.company_nbr, lc.last_contact from people AS p join lc 
> on p.person.nbr = lc.person_nbr;

Adrian,

Reformated and still has an error:
WITH lc AS (SELECT person_nbr, max(next_contact) AS last_contact
      from contacts where next_contact >= '2025-11-01'
      group by c.person_nbr)
select p.person_nbr, p.company_nbr, lc.last_contact
from people AS p
join lc on p.person.nbr = lc.person_nbr;

psql:companies-contacted-2025.sql:16: ERROR:  missing FROM-clause entry for table "c"
LINE 3:      group by c.person_nbr)

So, tweaking from reported errors:
WITH lc AS (SELECT p.person_nbr, max(c.next_contact) AS last_contact
      from people as p, contacts as c
      where next_contact >= '2025-11-01'
      group by p.person_nbr)
select p.person_nbr, p.company_nbr, lc.last_contact
from people AS p
join lc on p.person.nbr = lc.person_nbr;

psql:companies-contacted-2025.sql:9: ERROR:  missing FROM-clause entry for table "person"
LINE 7: join lc on p.person.nbr = lc.person_nbr;
                    ^
This is obviously a much more complicated query than I expected.

Thanks,

Rich