如何編寫此SQL Server查詢：在唯一行中添加值？

Question

我有一個像下面這樣的查詢。表格之間的關係是：

每輛卡車可能有多個司機。表列表將表卡車中的每一行與表格驅動程序中的行連接起來。現在我想在特定條件下獲得唯一卡車的數量，以及在這種情況下唯一卡車的總大小。

以下是我有：

SELECT t.Year AS [Year] 
     , t.Month AS [Month] 
     , t.Day AS [Day] 

     -- Count will not count NULL 
     , COUNT(DISTINCT (CASE WHEN (t.Sent = 1 AND r.Internal=1) THEN L.TruckId 
       ELSE NULL 
      END)) AS [Count] 

     , SUM(CASE WHEN (t.Sent = 1 AND r.Internal = 1) THEN t.Size 
      END) AS [Size] 

FROM Truck t 
INNER JOIN List L ON t.Id = L.TruckId 
     INNER JOIN Driver r ON L.DriverId = r.Id 
GROUP BY t.Year, t.Month, t.Day 

• 計數是正確的，但和不爲。

我的問題是如何得到這個SUM？ 我不想寫2個查詢並加入。

感謝

Answer 1

您可以嘗試像下面的查詢：

; with cte as (
SELECT 
    DISTINCT 
     t.Year AS [Year] 
    , t.Month AS [Month] 
    , t.Day AS [Day] 
    , L.TruckId, 
    , t.Size 
FROM Truck t 
INNER JOIN List L ON t.Id = L.TruckId 
INNER JOIN Driver r ON L.DriverId = r.Id 
WHERE t.Sent = 1 AND r.Internal=1 
) 
select 
     Year 
    , Month 
    , Day 
    , count(TruckId) AS [Count] 
    , sum(Size) AS [Size] 
from cte 
group by Year, Month, Day