TSQL动态数据透视表

Question

I am using a select statement like this...

SELECT FileYear, FileSemester, StudentID, AssessmentCode, AssessAreaHdgAbbrev1, AssessResultsResult
FROM vStudentReportsSemesterResults
WHERE (FileYear = 2014) AND (FileSemester = 2) AND (assessmentCode LIKE '11%') AND (AssessAreaHdgAbbrev2 = 'Grade')

This gives me

FileYear  FileSemester   StudentID   assessmentCode   AssessAreaHdgAbbrev1  AssessResultsResult
-------------------------------------------------------------------------------------------    
2014        2             41965        11ENGADV        Ass1                       C
2014        2             41965        11ENGADV        Ass2                       C
2014        2             41965        11ENGADV        Ass3                       C
2014        2             41965        11ENGADV        Prelim                       
2014        2             41965        11HISANC        Ass1                       A
2014        2             41965        11HISANC        Ass2                       B
2014        2             41965        11HISANC        Ass3                       B
2014        2             41965        11HISANC        Prelim                       
2014        2             41965        11HISMOD        Ass1                       B
2014        2             41965        11HISMOD        Ass2                       B
2014        2             41965        11HISMOD        Ass3                       
2014        2             41965        11HISMOD        Prelim                       
2014        2             41965        11MATGEN        Ass1                       B
2014        2             41965        11MATGEN        Ass2                       
2014        2             41965        11MATGEN        Prelim                       
2014        2             41965        11PEDPDH        Ass1                       B
2014        2             41965        11PEDPDH        Ass2                       B
2014        2             41965        11PEDPDH        Ass3                       
2014        2             41965        11PEDPDH        Ass4                       
2014        2             41965        11PEDPDH        Prelim                       

I would like to dynamically pivot the data to give me something which looks like

FileYear  FileSemester  StudentID  AssessmentCode  Ass1  Ass2  Ass3  Ass4  Prelim 
---------------------------------------------------------------------------------
2014        2            41965       11ENGADV        C    C    C        
2014        2            41965       11HISANC        A    B    B        
2014        2            41965       11HISMOD        B    B    
2014        2            41965       11MATGEN        B    
2014        2            41965       11PEDPDH        B    B    

Note that it has to be dynamic as the number of assessment points may change from subject to subject and year to year etc.

I have looked at information on this and tried to put together a dynamic pivot like

DECLARE @DynamicPivotQuery AS NVARCHAR(MAX)
DECLARE @ColumnName AS NVARCHAR(MAX)

select @ColumnName= ISNULL(@ColumnName + ',','') + QUOTENAME(AssessAreaHdgAbbrev1)
FROM (SELECT DISTINCT AssessAreaHdgAbbrev1 
FROM vStudentReportsSemesterResults
WHERE (FileYear = 2014) AND (FileSemester = 2) AND (AssessAreaHdgAbbrev2 = 'Grade') AND (AssessmentCode LIKE '11%')) AS Courses


SET @DynamicPivotQuery = N'
SELECT FileYear,  FileSemester, StudentID, AssessmentCode, AssessAreaHdgAbbrev1, AssessResultsResult
FROM vStudentReportsSemesterResults
WHERE (FileYear = 2014) AND (FileSemester = 2) AND (AssessAreaHdgAbbrev2 = ''grade'') AND (AssessmentCode LIKE ''11%'')
    PIVOT
    (
    MAX(AssessResultsResult) 
          FOR AssessAreaHdgAbbrev1 IN (' + @ColumnName + ')) AS PVTTable'

--Execute the Dynamic Pivot Query
EXEC sp_executesql @DynamicPivotQuery

I keep getting error messages like

Msg 156, Level 15, State 1, Line 5
Incorrect syntax near the keyword 'PIVOT'.

I am assuming this is because of the quotation marks or the where statement syntax. I am getting a little frustrated and was just wondering if anyone could have a look at my code and tell me how I could dynamically pivot the data so that it gives the Grades in columns rather than in separate rows.

Any help would be much appreciated.

---

Update

Thanks so much for your help.

My code now looks like...

DECLARE @DynamicPivotQuery AS NVARCHAR(MAX)
DECLARE @ColumnName AS NVARCHAR(MAX)

select @ColumnName= ISNULL(@ColumnName + ',','') + QUOTENAME(AssessAreaHdgAbbrev1)
FROM (SELECT DISTINCT AssessAreaHdgAbbrev1 
FROM vStudentReportsSemesterResults
WHERE (FileYear = 2014) AND (FileSemester = 2) AND (AssessAreaHdgAbbrev2 = 'Grade') AND (AssessmentCode LIKE '11%')) AS Courses

SET @DynamicPivotQuery = N'
SELECT 
FileYear,  
FileSemester, 
StudentID, 
AssessmentCode, 
AssessAreaHdgAbbrev1, 
AssessResultsResult
FROM (
SELECT * FROM vStudentReportsSemesterResults
WHERE (FileYear = 2014) 
    AND (FileSemester = 2) 
    AND (AssessAreaHdgAbbrev2 = ''grade'') 
    AND (AssessmentCode LIKE ''11%'')) src
PIVOT (MAX(AssessResultsResult) FOR AssessAreaHdgAbbrev1 IN (' + @ColumnName + ')) AS   PVTTable'

--Execute the Dynamic Pivot Query
EXEC sp_executesql @DynamicPivotQuery

when I run this I get

Msg 207, Level 16, State 1, Line 7
Invalid column name 'AssessAreaHdgAbbrev1'.
Msg 207, Level 16, State 1, Line 8
Invalid column name 'AssessResultsResult'.

Obviously it is not recognizing the fields for some reason. Any help would be greatly appreciated.

Answer 1

Try:

SELECT StudentID, '+@ColumnName+'
FROM (
SELECT * FROM vStudentReportsSemesterResults
WHERE (FileYear = 2014) 
    AND (FileSemester = 2) 
    AND (AssessAreaHdgAbbrev2 = ''grade'') 
    AND (AssessmentCode LIKE ''11%'')) src
PIVOT (MAX(AssessResultsResult) FOR AssessAreaHdgAbbrev1 IN (' + @ColumnName + ')) AS PVTTable

Generaly: SELECT * FROM (SELECT foo) AS Foo PIVOT ...

Look at documentation for PIVOT :

USE AdventureWorks2008R2;

GO
SELECT VendorID, [250] AS Emp1, [251] AS Emp2, [256] AS Emp3, [257] AS Emp4, [260] AS Emp5
FROM 
(SELECT PurchaseOrderID, EmployeeID, VendorID
FROM Purchasing.PurchaseOrderHeader) AS p
PIVOT
(
COUNT (PurchaseOrderID)
FOR EmployeeID IN
( [250], [251], [256], [257], [260] )
) AS pvt
ORDER BY VendorID;