sql - 在联合中共享行 - 分组？

Question

我有一个这样的查询：

SELECT * FROM (
   SELECT id, SUM( orderLineTotal ) as orderLine1, NULL as orderLine 2
   FROM Orders
   WHERE Orders.Date < @Today
   GROUP BY id

   UNION

   SELECT id, NULL as orderLine1, SUM(orderLineTotal2) as orderLine 2
   FROM Orders
   WHERE Orders.Date = @Today
   GROUP BY id
) o
GROUP BY o.id, o.orderLine1, o.orderLine2

我得到了这样的结果：

 ID         OrderLine1          OrderLine2
 -----------------------------------------
 1          105.00              NULL
 1          NULL                204.00
 2          49.30               NULL
 2          NULL                94.24

有没有办法修改查询以返回这样的内容？

 ID         OrderLine1          OrderLine2
 -----------------------------------------
 1          105.00              204.00
 2          49.30                94.24

Answer 1

你想用一个查询和条件聚合来做到这一点：

   SELECT id,
          SUM(case when Orders.Date < @Today then orderLineTotal end) as orderLine1, 
          SUM(case when Orders.Date = @Today then orderLineTotal2 end) as orderLine2
   FROM Orders
   GROUP BY id

orderLineTotal顺便说一句，真的有两列orderLineTotal2吗？我怀疑只有一个，第二个sum()应该相应地改变。