mysql - 分组依据似乎不适用于联合 SQL 查询

Question

这是我的 SQL 查询:

SELECT SUM(subtotal) 
FROM (
  SELECT SUM(product_price * how_many_purchased) as subtotal 
  FROM $table_name 
  WHERE location_id ='$location' 
    AND created_at >= '$startDate' 
    AND created_at <= '$endDate'  
UNION ALL 
SELECT SUM(shipping_total) 
FROM $table_name 
WHERE location_id ='$location' 
  AND created_at >= '$startDate' 
  AND created_at <= '$endDate' 
GROUP BY order_id) as subtotal");

使用分组依据进行的选择似乎没有分组。

Answer 1

如果您想对两个值求和，可以在单个查询中完成此操作。以下内容应按 order_id 给出总值(value):

  SELECT SUM(shipping_total) + SUM(product_price * how_many_purchased) as subtotal
  FROM $table_name
  WHERE location_id ='$location' AND created_at >= '$startDate' AND created_at <= '$endDate'
  GROUP BY order_id;

所有数据如下:

  SELECT SUM(shipping_total) + SUM(product_price * how_many_purchased) as subtotal
  FROM $table_name
  WHERE location_id ='$location' AND created_at >= '$startDate' AND created_at <= '$endDate';