This is your request, translated directly into SQL
select max(id) from sometable where sts=0 and ref_id IS NULL
Looking at your sample, it seems that sts is always 1 when ref_id exists, so it may possibly simplify to:
select max(id) from sometable where sts=0
-----Original Message-----
From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org] On Behalf Of Steve Clark
Sent: Thursday, June 2, 2016 9:56 AM
To: pgsql <pgsql-general@postgresql.org>
Subject: [GENERAL] dumb question
Hi List,
I am a noob trying to do something that seems like it should be easy but I can't figure it out.
I have a table like so:
id | ref_id | sts
------------------
1 | | 0
2 | 1 | 1
3 | | 0
4 | | 0
5 | 4 | 1
6 | | 0
7 | 6 | 1
I want to find the max(id) whose sts is 0 but whose id is not referenced by ref_id.
so the answer would be id=3.
Thanks for any pointers,
Steve
--
--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general