當總和沒有值時返回0總和 - sql server

Question

如果任何這些列沒有返回值，試着返回0，在我的特殊情況下，'Past Due'沒有總值，所以它被返回，所以我在這裏獲得第二個片段的回報。如果這些數值沒有數值，我該如何返回？

SELECT ClientDeliveryStatus, 
    SUM(CASE 
     WHEN ClientDeliveryStatus = 'Past Due' THEN 1 
     WHEN ClientDeliveryStatus = 'Due Tomorrow' THEN 1 
     WHEN ClientDeliveryStatus = 'Due Today' THEN 1 
     WHEN ClientDeliveryStatus = 'Due Beyond' THEN 1 
     ELSE 0 END) AS Total 
FROM Table1 
GROUP BY ClientDeliveryStatus 

當前結果：

ClientDeliveryStatus Total 
    Due Beyond    1 
    Due Today    3 
    Due Tomorrow   51 

所需的結果：

ClientDeliveryStatus Total 
    Due Beyond    1 
    Due Today    3 
    Due Tomorrow   51 
    Past Due    0 

實施例的數據：

TABLE1：

ClientDeliveryStatus 
Due Tomorrow 
Due Tomorrow 
Due Tomorrow 
Due Beyond 
Due Beyond 
Due Tomorrow 
Due Beyond 
Due Beyond 
Due Beyond 
Due Today 
Due Today 

CREATE TABLE1 Table1 (ClientDeliveryStatus VARCHAR(MAX)) 
INSERT INTO Table1 Values ('Due Tomorrow'), ('Due Tomorrow'), ('Due Tomorrow'), ('Due Beyond'), ('Due Beyond'), ('Due Beyond'), ('Due Beyond'), ('Due Today'),('Due Today') 

Answer 1

您需要一個包含所有狀態的表格。如果你不已經有一個表，你可以在查詢本身做到這一點：

SELECT ClientDeliveryStatus, COUNT(t.ClientDeliveryStatus) AS Total 
FROM (SELECT 'Past Due' as cds UNION ALL 
     SELECT 'Due Tomorrow' UNION ALL 
     SELECT 'Due Today' UNION ALL 
     SELECT 'Due Beyond' 
    ) s LEFT JOIN 
    Table t 
    ON s.cds = t.ClientDeliveryStatus 
GROUP BY s.cds; 

你原來的查詢不正確，因爲它缺少一個GROUP BY和過於複雜，因爲在SUM()的CASE的。