:ladder_table
+------------+-------------+
| Field      | Type        |
+------------+-------------+
| user_id    | smallint(6) |
| ladder_id  | smallint(6) |
+------------+-------------+

##</code><code>##

DELETE from ladder_table where ladder_id = 2345

##</code><code>##

UPDATE ladder_table 
SET ladder_ranking = ladder_ranking -1 
WHERE ladder_ranking >= 17 
AND ladder_ranking < 2345

##</code><code>##

UPDATE ladder_table SET ladder_ranking = 7 WHERE user_id = 0034