MSSQL 2005查询组日期 - 甚至没有记录的日期？

Question

我有这样的MS SQL 2005查询：

SELECT 
    DATEDIFF(dd, getdate(), CreatedOn) as Day, 
    COUNT(CreatedOn) as 'Active Cases' 
FROM 
    [dbo].[IncidentBase] 
WHERE 
    (StatusCode != 6 AND StatusCode != 5) 
    AND (CaseTypeCode = '200000' OR CaseTypeCode = '200005' OR CaseTypeCode = '200006') 
GROUP BY 
    DATEDIFF(dd, getdate(), CreatedOn) 
ORDER BY 
    Day DESC 

，并返回这样的事情：

-1 10 
-2 6 
-5 4 
-7 8 

我真的想它是这样的：

-1 10 
-2 6 
-3 0 
-4 0 
-5 4 
-6 0 
-7 8 

（之间插入零日期没有记录）

我该怎么做？

非常感谢提前！

Answer 1

尝试外部连接的子查询返回的所有日期

SELECT table_cal.day_diff as "Day", 
    COALESCE(table_count.base_count,0) as "Active Cases" 
FROM 
(SELECT DISTINCT DATEDIFF(dd, getdate(), ibase.CreatedOn) as day_diff 
    FROM [dbo].[IncidentBase] ibase) table_cal 
LEFT OUTER JOIN 
(SELECT DATEDIFF(dd, getdate(), ibase.CreatedOn) as day_diff, 
    COUNT(ibase.CreatedOn) as base_count 
    FROM [dbo].[IncidentBase] ibase 
    WHERE ibase.StatusCode NOT IN (5,6) AND ibase.CaseTypeCode IN ('200000','200005','200006') 
    GROUP BY DATEDIFF(dd, getdate(), ibase.CreatedOn)) table_count 
ON (table_cal.day_diff = table_count.day_diff) 
ORDER BY table_cal.day_diff DESC 

背后的想法很简单。您需要一个子查询来生成现有日期的列表，另一个用于生成结果值。然后你外连接并且用0替换空值。