You can't specify target table 'item' for update in FROM clause

今天写sql处理历史数据时，报出标题的错误，sql如下:

UPDATE item SET platf_min_sell_price = NULL, platf_max_sell_price = NULL WHERE item_id IN ( SELECT DISTINCT item_id FROM item_sku WHERE sku_id IN ( SELECT sku_id FROM trade_sku_price WHERE item_id IN ( SELECT item_id FROM item WHERE platform_id = 123456 AND platf_min_sell_price IS NOT NULL AND platf_max_sell_price IS NOT NULL ) ) AND attributes IS NOT NULL )

意思大概就是你不能一边查着item表一边修改它，否则可能会引起问题。 stackoverflow给出的一种解决办法是，把子句查询结果存放到临时表中，修改后的sql如下：

UPDATE item SET platf_min_sell_price = NULL, platf_max_sell_price = NULL WHERE item_id IN ( SELECT item_id FROM ( ( ( SELECT DISTINCT item_id FROM item_sku WHERE sku_id IN ( SELECT sku_id FROM trade_sku_price WHERE item_id IN ( SELECT item_id FROM item WHERE platform_id = 123456 AND platf_min_sell_price IS NOT NULL AND platf_max_sell_price IS NOT NULL ) ) AND attributes IS NOT NULL ) ) ) AS t )