SQL更新表使用另一个查询的结果

Question

在计算完订单的总金额后，我试图更新表格（订单），我成功地计算了总金额，但是我找不到使用结果更新表格的方法。

代码我成功计算了总金额：

SELECT orders.orderid, 
       SUM(ordersdish.quantity*dish.price) AS total
FROM   dish 
JOIN   ordersdish 
       ON ordersdish.dishid = dish.dishid 
JOIN   orders 
       ON orders.orderid = ordersdish.orderid 
GROUP BY orders.orderid;

结果： total amount

我尝试更新表格（订单）的代码：

UPDATE orders
SET    total = t1.total
FROM   (
        SELECT orders.orderid, 
               SUM(ordersdish.quantity*dish.price) AS total
        FROM   dish 
        JOIN   ordersdish 
               ON ordersdish.dishid = dish.dishid 
        JOIN   orders 
               ON orders.orderid = ordersdish.orderid 
       GROUP BY orders.orderid  
      )t1
 WHERE  orders.orderid = t1.orderid;

MySQL说：

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'from
(select orders.orderid, SUM(ordersdish.quantity*dish.price)as total
from ' at line 3

这是表格“ orders”：

Answer 1

MySQL中正确的语法使用JOIN：

update orders o join
       (select od.orderid, SUM(od.quantity * d.price)as total
        from dish d join
             ordersdish od
             on od.dishid = d.dishid  
        group by od.orderid
       ) t1
       on o.orderid = t1.orderid
    set o.total = t1.total;

请注意，子查询中不需要orders，因为orderid在orderdish中。

Answer 2

请尝试此答案。

UPDATE o
SET o.total = t1.total
(SELECT o.orderid, SUM(od.quantity * d.price) AS total 
FROM dish AS d 
JOIN ordersdish AS od ON od.dishid = d.dishid 
JOIN orders AS o ON o.orderid = od.orderid 
GROUP BY orders.orderid) t1
WHERE o.orderid = t1.orderid;