我有以下查詢:
delete from customers_cards where id not in ( select min(id) from customers_cards group by number_card ) and belongs_to = "ezpay"
它報錯:
#1093 - 在FROM子句中,不能為更新指定目標表'customers_cards'
我猜我需要使用join
作為一種解決方法,但老實說,我無法使用join
重寫相同的邏輯。有沒有辦法用join
來編寫上面的查詢?
這里是另一種方法:
刪除屬于 'ezpay' 的任何行 c1
,前提是存在另一行 c2
,它具有相同的 number_card
和較小的 id
。
DELETE c1 FROM customer_cards AS c1 LEFT OUTER JOIN customers_cards AS c2 ON c1.number_card = c2.number_card AND c1.id > c2.id WHERE c2.id IS NOT NULL AND c1.belongs_to = 'ezpay';
這個連接應(yīng)該類似于你在一個表中選擇行但不在另一個表中選擇的方法。
DELETE c1 FROM customers_cards AS c1 LEFT JOIN ( SELECT MIN(id) AS id FROM customer_cards GROUP BY number_card ) AS c2 ON c1.id = c2.id WHERE c2.id IS NULL AND c1.belongs_to = 'ezpay'