How to select maximum 3 items per users in MySQL?

Question

I run a website where users can post items (e.g. pictures). The items are stored in a MySQL database.

I want to query for the last ten posted items BUT with the con

Answer 1

It's pretty easy with a correlated sub-query:

SELECT `img`.`id` , `img`.`userid`
FROM `img`
WHERE 3 > (
SELECT count( * )
FROM `img` AS `img1`
WHERE `img`.`userid` = `img1`.`userid`
AND `img`.`id` > `img1`.`id` )
ORDER BY `img`.`id` DESC
LIMIT 10 

The query assumes that larger id means added later

Correlated sub-queries are a powerful tool! :-)