Re: Extract only maximum date from column

Bryan Sayer <blslists@gmail.com>

From: Bryan Sayer <blslists@gmail.com>
To: pgsql-general@lists.postgresql.org
Date: 2025-12-04T20:01:46Z
Lists: pgsql-general
I believe in general you need

having c.next_contact = max(c.next_contact)

(at least in ANSI SQL) Use having for after the join has occured

*Bryan Sayer*
Retired Demographer/Statistician
/In a world in which you can be anything, *be kind*/
On 12/4/2025 2:55 PM, Rich Shepard wrote:
> I want the script to extract only the maximum `next_contact' date and
> haven't learned how to do this from my reading of web sites.
>
> The script:
>
> select p.person_nbr, p.company_nbr, c.next_contact
> from people as p, contacts as c
> where c.next_contact >= '2025-11-01'
> group by p.person_nbr, p.company_nbr, c.next_contact
> order by p.person_nbr, p.company_nbr, max(c.next_contact);
>
> returns all contacts rather than only the latest one.
>
> Is using a sub-select the proper way?
>
> TIA,
>
> Rich
>
>