SQL服務器（避免了空值除以）

Question

我有以下查詢：

UPDATE FinanceTable 
SET PercentageComplete = (SELECT (Sum(LabourFinance.HoursTaken/LabourFinance.Hours)/Count(LabourID)) 
          FROM LabourFinance 
          WHERE FinanceID = (SELECT TOP 1 FinanceID 
               FROM FinanceTable 
               ORDER BY changedate DESC) 
          GROUP BY FinanceID) 
WHERE FinanceID = (SELECT TOP 1 FinanceID 
        FROM FinanceTable 
        ORDER BY changedate DESC) 

什麼這個查詢的作用是選擇基於CHANGEDATE 1個特定的細胞，我使用更新的成本值在我的FinanceTable中。

這種情況導致了我的問題：

• 我已撥出百小時插入表格後完成任務
• HoursTaken目前0作爲計算PercntageComplete時，香港專業教育學院尚未啓動
• ，SQL Server不會讓我這樣做（0/100），因此導致錯誤...

我該如何防止這種情況？我期望的結果將是PercentageComplete = 0%

感謝任何輸入:)下面是錯誤消息我得到運行過程中出現上述

Answer 1

查詢推薦本

How to avoid the 「divide by zero」 error in SQL?

UPDATE FinanceTable 
SET PercentageComplete = (SELECT COALESCE (Sum(COALESCE (LabourFinance.HoursTaken/NULLIF(LabourFinance.Hours, 0), 0))/NULLIF(Count(LabourID), 0), 0) 
          FROM LabourFinance 
          WHERE FinanceID = (SELECT TOP 1 FinanceID 
               FROM FinanceTable 
               ORDER BY changedate DESC) 
          GROUP BY FinanceID) 
WHERE FinanceID = (SELECT TOP 1 FinanceID 
        FROM FinanceTable 
        ORDER BY changedate DESC)