Calculate position based on a value

Thank you but I had already made the correction.
I have trouble writing my fuction.
Someone an idea to move me please

With this fields: from_user_id, total_stats

You can order by total_stats and get the rank position without update another table:

Code:

SELECT from_user_id, total_stats, position FROM
    (
    SELECT t.from_user_id, total_stats,
        @rownum := @rownum + 1 AS position
    FROM score t, (SELECT @rownum := 0) r
    ORDER BY total_stats DESC
    ) as table_position

And for a single user too:

Code:

SELECT from_user_id, total_stats, position FROM
    (
    SELECT t.from_user_id, total_stats,
        @rownum := @rownum + 1 AS position
    FROM score t, (SELECT @rownum := 0) r
    ORDER BY total_stats DESC
    ) as table_position
WHERE from_user_id = 25032