当没有要求和的值时，总和返回 0 - sql server

Question

Trying to return 0 if any of these columns have no values returned, in my particular case 'Past Due' has no values to total, so it is returned, so i get the return in the second snippet here. How can I return something if these are no values to count?

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

Current Result:

    ClientDeliveryStatus    Total
    Due Beyond              1
    Due Today               3
    Due Tomorrow            51

Desired Result:

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

Example data:

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

You need a table of all the statuses. If you don't already have a table, you can do this in the query itself:

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;

Your original query is incorrect because it is missing a GROUP BY and overly complicated because of the CASE in the SUM() .