Duplicate message remover sql

DELETE FROM messages
WHERE primary_key IN (
    SELECT msg.primary_key FROM messages AS msg
    INNER JOIN (
        SELECT MAX(primary_key) AS biggest_primary_key, message_id
        FROM messages
        GROUP BY message_id
        HAVING COUNT(message_id) > 1
    ) AS dup
    WHERE msg.message_id = dup.message_id AND msg.primary_key < dup.biggest_primary_key
)