Change Rows to Columns in SQL Server - sql

Question

I've been working on this query for an hour and half but I can't get it done,
First, this is my query:
SELECT
Questions, PossibleAnswer,
((COUNT(PossibleAnswer) + 0.0) / 10 ) * 100 AS Percentage
FROM
(SELECT
A.AnswerID, B.Questions, B.QuestionID, C.PossibleAnswer
FROM
TblSurveyCustomerAnswers A
INNER JOIN
TblSurveyQuestion B ON A.QuestionID = B.QuestionID
INNER JOIN
TblSurveyAnswer C ON A.AnswerID = C.AnswerID
WHERE
A.CustomerID = 1) AS SOURCE
GROUP BY
Questions, PossibleAnswer
The result is below:
Now, I want the rows for column name PossibleAnswer to be converted in columns, so I did a research and found the PIVOT command (I need dynamic since it's a possible answers field) and this is my code
DECLARE #DynamicPivotQuery AS NVARCHAR(MAX)
DECLARE #ColumnName AS NVARCHAR(MAX)
--Get distinct values of the PIVOT Column
SELECT #ColumnName= ISNULL(#ColumnName + ',','')
+ QUOTENAME(PossibleAnswer)
FROM
(
SELECT DISTINCT X.*
FROM
(
SELECT Questions,PossibleAnswer, ((COUNT(PossibleAnswer) + 0.0) / 10 ) * 100 AS Percentage
FROM
(
SELECT A.AnswerID,B.Questions, B.QuestionID, C.PossibleAnswer
FROM TblSurveyCustomerAnswers A
INNER JOIN TblSurveyQuestion B
ON A.QuestionID = B.QuestionID
INNER JOIN TblSurveyAnswer C
ON A.AnswerID = C.AnswerID
WHERE A.CustomerID = 1
) AS SOURCE
GROUP BY Questions, PossibleAnswer
) X
) AS B
--Prepare the PIVOT query using the dynamic
SET #DynamicPivotQuery =
'SELECT Questions, ' + #ColumnName + '
FROM TblSurveyCustomerAnswers A
INNER JOIN TblSurveyQuestion B
ON A.QuestionID = B.QuestionID
PIVOT(Max(Questions)
FOR PossibleAnswer IN (' + #ColumnName + ')) AS PVTTable'
--Execute the Dynamic Pivot Query
EXEC sp_executesql #DynamicPivotQuery
And I can't get the pivot work, need help. I'm stuck. See this error:

Answer 1

In general for questions like these you should provide sample data, table definitions and expected output so people can take your script, fiddle with it and produce something that works. See How to post a T-SQL question on a public forum for one way to do this.
Since it is hard to look at a dynamic script, not having the table structures, and point at what your problem is, let me give you the following advice:
Instead of taking your big query that produces the output and form queries around that big query, first insert the output of that query into a temporary table. You can do this by placing an INTO #temp_table clause after the SELECT clause. This creates a new temporary table #temp_table containing the output of the query.
SELECT --your select columns
INTO #p_in -- creates a temporary table #p_in that contains the output
FROM --the rest of your query
Determine the pivot columns based on the newly created temporary table. It'll be a lot more conscise and easier to spot errors
Write your Dynamic SQL using the temporary table (again it'll be a lot more conscise and easier to spot errors)
Don't forget to DROP the temporary table after executing the dynamic SQL.

Answer 2

I just try to solved problem without temporary table. You may edit query as your requirement.
--For PIVOT column
DECLARE #ColumnName AS NVARCHAR(MAX)
SELECT #ColumnName ''''+ PossibleAnswer + '''' + ' , ' + #ColumnName
FROM
(
SELECT
DISTINCT PossibleAnswer
FROM
(
SELECT
A.AnswerID, B.Questions, B.QuestionID, C.PossibleAnswer
FROM
TblSurveyCustomerAnswers A
INNER JOIN
TblSurveyQuestion B ON A.QuestionID = B.QuestionID
INNER JOIN
TblSurveyAnswer C ON A.AnswerID = C.AnswerID
WHERE
A.CustomerID = 1
) AS SOURCE
)B
--For removing last comma
IF #ColumnName != ''
BEGIN
SET #ColumnName = SUBSTRING(#ColumnName, 1, LEN(#ColumnName)-1)
END
-- Make result
SELECT *
FROM
(
SELECT Questions,PossibleAnswer, ((COUNT(PossibleAnswer) + 0.0) / 10 ) * 100 AS Percentage
FROM
(
SELECT A.AnswerID,B.Questions, B.QuestionID, C.PossibleAnswer
FROM TblSurveyCustomerAnswers A
INNER JOIN TblSurveyQuestion B
ON A.QuestionID = B.QuestionID
INNER JOIN TblSurveyAnswer C
ON A.AnswerID = C.AnswerID
WHERE A.CustomerID = 1
) AS SOURCE
GROUP BY Questions, PossibleAnswer
)C
PIVOT
( Max(Questions)
FOR PossibleAnswer IN (#ColumnName)
) AS PVTTable