Question

我有两张表Orders和Order_Details Order_Details个表的order_id字段充当Orders表的id_order表的外键。

我想更新price_total表的Orders字段，其中包含Order_Details表中的价格总和。

我尝试使用以下查询但失败了： -

Update Orders, Order_Details
  SET  Orders.price_total = sum(Order_Details.price)
 WHERE Orders.price_total=0
 GROUP BY Order_Details.id_order

错误 -

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'GROUP BY Order_Details.id_order' at line 4

如何在一个查询中执行此操作？

由于

Answer 1

您可以将其简化为

Update Orders 
SET Orders.price_total = 
(
  SELECT 
    sum(Order_Details.price) 
  FROM Order_Details 
  WHERE 
    Orders.id_order=Order_Details.order_id
)
WHERE Orders.price_total=0;

<击> 更新进行分组

Update Orders, Order_Details SET Orders.price_total = sum(Order_Details.price) WHERE Orders.price_total=0 AND Orders.id_order=Order_Details.order_id GROUP BY Order_Details.id_order

<击>

使用表连接的Mysql更新 - 使用其他表的字段的总和更新一个表的字段

1 个答案: