ALTER TABLE db_version CHANGE COLUMN required_10263_02_mangos_pool_gameobject required_10263_03_mangos_pool_pool bit; DROP TABLE IF EXISTS pool_pool_temp; CREATE TABLE pool_pool_temp SELECT pool_id, mother_pool, chance, description FROM pool_pool GROUP BY pool_id; ALTER TABLE pool_pool_temp ADD PRIMARY KEY (pool_id), ADD INDEX pool_idx (mother_pool); DROP TABLE IF EXISTS pool_pool; RENAME TABLE pool_pool_temp TO pool_pool;