SQL Query GROUP LIKE

Question

我有一個表格，用於捕獲每個計算錯誤代碼。我有內部（20K故障碼）和外部（60K故障代碼）我是根據故障碼的總數關

這裏算我的數據塊的樣子：

FaultCode Count 
20001  200 
20002  100 
60004  300 
60034  80 

以下代碼會給我每個FaultCode的COUNT。

SELECT FaultCode, COUNT(FaultCode) AS COUNT 
FROM RmaSummary 
WHERE ClosedTime IS NULL AND (FaultCode LIKE '60%' OR FaultCode LIKE '20%') 
GROUP BY FaultCode 

但是，我想要得到的faultcode LIKE '60％ 'OR LIKE '20％FaultCodes' 總和，例如：

FaultCode  COUNT 
60k   380 
20K   300 

有什麼建議？

Answer 1

可以使用case表達式組值：

SELECT 
    CASE 
     WHEN FaultCode LIKE '60%' THEN '60K' 
     WHEN FaultCode LIKE '20%' THEN '20K' 
    END AS FaultCode 
    , COUNT(FaultCode) AS COUNT 
FROM RmaSummary 
WHERE ClosedTime IS NULL AND (FaultCode LIKE '60%' OR FaultCode LIKE '20%') 
GROUP BY 
    CASE 
     WHEN FaultCode LIKE '60%' THEN '60K' 
     WHEN FaultCode LIKE '20%' THEN '20K' 
    END 

如果你不想重複case表達您可以在部分移動到一個派生表或公共表表達式（如果你的數據庫支持那）。