Question

I need to get the last inserted product by a user. This is what I’ve came up with

   $query = 'SELECT id
                 FROM products
                 WHERE user_id = ?
                ORDER BY id DESC
                       LIMIT 1';

It should work because the id is auto increment. To me though, it feels hacky. Is there a better way to do this?

I can’t use mysql_last_insert_id() or anything like that because I need the last product by a specific user.

Answer 1

Use:

  SELECT MAX(t.id) AS id
    FROM PRODUCTS t
   WHERE t.user_id = ?

MAX is an aggregate function, returning the maximum value of the column specified. Because the query is only returning one column – the one the aggregate function is being used on – the GROUP BY clause doesn’t need to be specified. But there’s no harm in using:

  SELECT MAX(t.id) AS id
    FROM PRODUCTS t
   WHERE t.user_id = ?
GROUP BY t.user_id