Question

Hi i have an issue with a mysql select statement i cant get my head around,

Table client_directory_data

id int,
verified int,
client_id int,
created timestamp,
description longtext

select * from client_directory_data where verified = 1 order by created desc

but this selects multiple rows for each client_id

what i need to do is to select every client_id which has a verified = 1 but only get the most recent row for each client_id, i hope that makes sense.

Answer 1

That makes sense and is a classic question.

Assuming that the most recent row is the one with highest id, you can use:

SELECT *
FROM client_directory_data c
LEFT JOIN client_directory_data d ON c.client_id = d.client_id AND d.verified = 1 AND d.id > c.id
WHERE d.id IS NULL
    AND c.verified = 1;

You can have an explanation of this query pattern here.