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

Question

I have two tables Orders and Order_Details Order_Details tables's order_id field acts as foreign key to Orders table's id_order table.

I want to update the price_total field of Orders table with summation of prices from Order_Details table.

I tried with the following query but failed:-

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

Error -

#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

How to do it in one query?

Thanks

Answer 1

You can simplify it to

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;

for grouping

 
 
 
  
  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