转置计数从水平到垂直

Question

有没有办法在SQL Server 2008中将结果从水平转换为垂直？

例如，我在下面有下面的查询。

Select 
(Select Count(*) FROM tblJob Where JobOwnerID = e.EmployeeID) AS JobTotal, 
(Select Count(*) FROM tblJob Where JobOwnerID = e.EmployeeID and Status = 'Completed') AS JobTCompleted, 
(Select Count(*) FROM tblJob Where JobOwnerID = e.EmployeeID and Status = 'Expried') AS JobExpired 
FROM tblEmployee e 

然后该查询产生下面的结果：

RecID JobTotal JobCompleted JobExpired 
1574 167   56    167 
1621 216   85    215 
1676 8   2    5 

我想从该结果到垂直格式如下样品转置。

RecID Category FieldName  Value 
1574 Job   JobTotal  167 
1574 Job   JobCompleted 56 
1574 Job   JobExpired  167 
1621 Job   JobTotal  216 
1621 Job   JobCompleted 85 
1621 Job   JobExpired  215 
1676 Job   JobTotal  8 
1676 Job   JobCompleted 2 
1676 Job   JobExpired  5 

请指教（如有可能，带示例代码）。在此先感谢

Answer 1

你会发现这个性能会更好，因为它避免了重复聚集一招。

WITH J 
    AS (SELECT JobOwnerID, 
       COUNT(*) AS JobTotal, 
       COUNT(CASE 
         WHEN Status = 'Completed' THEN 1 
         END) AS JobTCompleted, 
       COUNT(CASE 
         WHEN Status = 'Expried' THEN 1 
         END) AS JobExpired 
     FROM tblJob 
     GROUP BY JobOwnerID) 
SELECT e.RecID, 
     v.FieldName, 
     ISNULL(Value, 0) AS Value 
FROM tblEmployee e 
     LEFT JOIN J 
       ON J.JobOwnerID = E.EmployeeID 
     CROSS APPLY (VALUES ('JobTotal', JobTotal), 
          ('JobCompleted', JobTCompleted), 
          ('JobExpired', JobExpired)) V(FieldName, Value) 

Answer 2

下面是使用Outer Apply

SELECT RecID, 
     Category, 
     FieldName, 
     Count(FieldName) 
FROM tblEmployee e 
     Left join tblJob t on t.JobOwnerID = e.EmployeeID 
     Outer apply (SELECT 'JobTCompleted' WHERE Status = 'Completed' 
        UNION ALL 
        SELECT 'JobExpired' WHERE Status = 'JobExpired' 
        UNION ALL 
        SELECT 'JobTotal') cs (FieldName) 
Group By RecID, 
     Category, 
     FieldName 

Answer 3

您可以将您从原始查询中获得的结果数据集取消转换。

;WITH RESULT_TABLE AS 
(Select e.RecID 
(Select Count(*) FROM tblJob Where JobOwnerID = e.EmployeeID) AS JobTotal, 
(Select Count(*) FROM tblJob Where JobOwnerID = e.EmployeeID and Status = 'Completed') AS JobTCompleted, 
(Select Count(*) FROM tblJob Where JobOwnerID = e.EmployeeID and Status = 'Expried') AS JobExpired 
FROM tblEmployee e) 
SELECT RecID,[Option],[Value] 
FROM 
RESULT_TABLE 
UNPIVOT 
(
    [Value] FOR [Option] IN (JobTotal,JobCompleted,JobExpired) 
) AS unpivotTable;