SQL SUM CASE 語句

Question

我有：

SUM
(
case
when LC.[DWC] = 0 and LC.BI = 1 then 1
else LC.[DWC] END AS DC
) 
AS [DWC]

但我收到一條錯誤消息：

“SUM”不是可識別的內置函數名稱。

我怎樣才能解決這個問題？

Answer 1

假設您使用的是 sql-server：

Select SUM(CASE WHEN (LC.[DWC] = 0 and LC.BI = 1) THEN 1 ELSE LC.[DWC] END) AS [DWC] 
FROM LC