Re: Selecting records with highest timestamp - for a join

On 10/19/2016 12:44 PM, Alexander Farber wrote:
> Adrian, for both player1 and player2 (because I need to display player
> photos above the game board).
>
> SQL join with words_social - yes, but how to take the most recent record
> from that table?
>
> For example there are user infos from Google+, Facebook, Twitter - but
> the user has used Facebook to login lately and would expect her
> Facebook-photo to be seen (the record with the highest "stamp" value).

I have not dug into your function deep enough to understand all the relationships
involved so I cannot offer anything specific. A generic method:

test[5432]=# create table ts_stamp_test(id serial PRIMARY KEY, uid integer, stamp integer NOT NULL);
CREATE TABLE
test[5432]=# insert into ts_stamp_test (uid, stamp) values (1, 5), (2, 10), (1, 12), (2, 15), (1, 18), (2, 30);
INSERT 0 6
test[5432]=# select * from ts_stamp_test;
id | uid | stamp
----+-----+-------
1 | 1 | 5
2 | 2 | 10
3 | 1 | 12
4 | 2 | 15
5 | 1 | 18
6 | 2 | 30
(6 rows)

test[5432]=# select * from ts_stamp_test where uid = 1 order by stamp desc limit 1;
id | uid | stamp
----+-----+-------
5 | 1 | 18
(1 row)

>
> Regards
> Alex
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com