加入動態SQL當建築物立柱頭

Question

我有以下兩個表：

測驗表：

QuizNo | Status 
    1  Reviewed 
    2  Not Reviewed 

測驗響應表：

QuizNo | QuestionID | Response 
1    11   Yes 
2    13   No 
2    11   Yes 
1    13   No 

這是預期的結果（11 13是問號ID）：

QuizNo | Status  | 11 | 13 
    1  Reviewed  Yes  No 
    2  Not Reviewed Yes  No 

這是我目前的查詢，這是不正常：

DECLARE @cols AS NVARCHAR(MAX), 
    @query AS NVARCHAR(MAX) 

select @cols = STUFF((SELECT ',' + QUOTENAME(QuestionID) 
        from Quiz 
        INNER JOIN QuizResponse x ON QuizNo = x.QuizNo 
        group by QuestionID, QuizNo 
        order by QuestionID 
      FOR XML PATH(''), TYPE 
      ).value('.', 'NVARCHAR(MAX)') ,1,1,'') 

set @query = N'SELECT ' + @cols + N' from 
      (
       select QuestionID 
       from QuizResponse 
      ) x 
      pivot 
      (
       max(QuestionID) 
       for QuestionID in (' + @cols + N') 
      ) p ' 

exec sp_executesql @query; 

你將如何完成/更改查詢，以獲得預期的結果？

TIA！

Answer 1

你接近，但有查詢之前需要幾件事情可能是完整的。

Stuff函數中的Query需要同時指定QuizNo和表別名。它也不應該按QuizID進行分組，否則最終會出現重複的列定義（每個QuizID帶有一個QuestionID 11，每個列定義一個[11]）。所以整理了一下。

最後，更新動態SQL以選擇未被旋轉的列，並​​選擇max（Response）而不是QuestionID作爲每個單元格的數據。

請參閱SQLFiddle example。

DECLARE @cols AS NVARCHAR(MAX), 
    @query AS NVARCHAR(MAX) 

select @cols = STUFF((SELECT ',' + QUOTENAME(QuestionID) 
        from Quiz Q 
        INNER JOIN QuizResponse x ON Q.QuizNo = x.QuizNo 
        GROUP BY QuestionID 
        ORDER BY QuestionID 
      FOR XML PATH(''), TYPE 
      ).value('.', 'NVARCHAR(MAX)') ,1,1,'') 

set @query = N'SELECT QuizNo, [Status], ' + @cols + N' from 
      (
       select QR.QuizNo, Q.[Status], QR.QuestionID, QR.Response 
       from QuizResponse QR 
        inner join Quiz Q on QR.QuizNo = Q.QuizNo 
      ) x 
      pivot 
      (
       max(Response) 
       for QuestionID in (' + @cols + N') 
      ) p ' 

exec sp_executesql @query; 

Answer 2

我會做這個使用條件彙總：

select q.quizno, q.status, 
     max(case when qr.questionid = 11 then qr.response end) as [11], 
     max(case when qr.questionid = 13 then qr.response end) as [13] 
from quiz q join 
    quizreponse qr 
    on qr.quizno = q.quizno 
group by q.quizno, q.status;