Trouble with PIVOT in SQL (Azure SQL) - sql

Question

I need to list survey responses in one row. The table of survey responses lists a questionID and a ResponseID (these are multiple choice questions), so one row for each response. There are 12 questions. Things like the date of the response, worker who conducted the survey, and worker who entered the survey are kept in other tables.
So, I have a query that gets the responses for one survey into 12 rows. Now I need to get all that into one row. Pivot, right?
But I could never get it to work. :-( Tried several solutions from this and other fora (including Mickey's documentation here: https://learn.microsoft.com/en-us/sql/t-sql/queries/from-using-pivot-and-unpivot?view=sql-server-2017).
Then I found this solution, that doesn't use pivot at all, here: SQL Pivot Table Grouping
It worked great, but the example has only two questions. Some of our surveys will have over 50 questions, so I'm guessing that won't be a very elegant solution.
So I'm back to my pivot issue.
Experience level is somewhere between idiot and novice, so I'm probably missing something obvious.
Here's the query by itself (works as expected):
SELECT AssessmentResponses.ID, AssessmentQuestions.QuestionNumber,
AssessmentResponseAnswers.QuestionID,
AssessmentAnswerChoices.AnswerChoiceNumber
FROM (AssessmentResponses RIGHT JOIN AssessmentResponseAnswers
ON AssessmentResponses.ID = AssessmentResponseAnswers.AssessmentResponseID)
LEFT JOIN (AssessmentQuestions RIGHT JOIN AssessmentAnswerChoices
ON AssessmentQuestions.ID = AssessmentAnswerChoices.AssessmentQuestionID)
ON AssessmentResponseAnswers.AnswerChoiceID = AssessmentAnswerChoices.AnswerChoiceID
WHERE AssessmentResponses.AssessmentID = 1 AND AssessmentResponses.RespondentID = 44;
Here's how I tried to make it pivot:
SELECT ID, [1A], [1B], [2A], [2B], [3A], [3B], [4A], [4B], [5A], [5B], [6A], [6B]
FROM (
SELECT AssessmentResponses.ID, AssessmentQuestions.QuestionNumber,
AssessmentResponseAnswers.QuestionID,
AssessmentAnswerChoices.AnswerChoiceNumber
FROM (AssessmentResponses RIGHT JOIN AssessmentResponseAnswers
ON AssessmentResponses.ID = AssessmentResponseAnswers.AssessmentResponseID)
LEFT JOIN (AssessmentQuestions RIGHT JOIN AssessmentAnswerChoices
ON AssessmentQuestions.ID = AssessmentAnswerChoices.AssessmentQuestionID)
ON AssessmentResponseAnswers.AnswerChoiceID = AssessmentAnswerChoices.AnswerChoiceID
WHERE AssessmentResponses.AssessmentID = 1 AND AssessmentResponses.RespondentID = 44
) AS Src
PIVOT
(
MAX(AnswerChoiceNumber)
FOR QuestionNumber IN ([1A], [1B], [2A], [2B], [3A], [3B], [4A], [4B], [5A], [5B], [6A], [6B])
)
AS Pvt;
I was hoping that would give me 1 row with 13 columns (ID plus the twelve questions). But it gave me still 12 rows: the 13 columns are there, and it just gives null values for 11 of the twelve questions. (In row1, 1A has an answer; in row2, 1B has an answer, etc.)
What am I missing?

Answer 1

Tweaked your code just a bit to get rid of "QuestionID" in the subquery. It is not involved in what you're pivoting on, so SQL Server will think it's one of your keys.
SELECT ID, [1A], [1B], [2A], [2B], [3A], [3B], [4A], [4B], [5A], [5B], [6A], [6B]
FROM (
SELECT AssessmentResponses.ID, AssessmentQuestions.QuestionNumber,
AssessmentAnswerChoices.AnswerChoiceNumber
FROM (AssessmentResponses RIGHT JOIN AssessmentResponseAnswers
ON AssessmentResponses.ID = AssessmentResponseAnswers.AssessmentResponseID)
LEFT JOIN (AssessmentQuestions RIGHT JOIN AssessmentAnswerChoices
ON AssessmentQuestions.ID = AssessmentAnswerChoices.AssessmentQuestionID)
ON AssessmentResponseAnswers.AnswerChoiceID = AssessmentAnswerChoices.AnswerChoiceID
WHERE AssessmentResponses.AssessmentID = 1 AND AssessmentResponses.RespondentID = 44
) AS Src
PIVOT
(
MAX(AnswerChoiceNumber)
FOR QuestionNumber IN ([1A], [1B], [2A], [2B], [3A], [3B], [4A], [4B], [5A], [5B], [6A], [6B])
)
AS Pvt;
I imagine you're used to the designer. A few tips (not implemented above) to make code more readable:
You can usually omit parentheses around your join statements
I'd re-work your joins to associate one on-statement per join statement
Aliases!

Answer 2

In my opinion this is not exactly a work to do with pivot. Maybe like this:
SELECT ar.ID
,(
SELECT aac.AnswerChoiceNumber
FROM AssessmentResponseAnswers ara, AssessmentAnswerChoices aac, AssessmentQuestions aq
WHERE ar.ID=ara.AssessmentResponseID
AND ara.AnswerChoiceID=aac.AnswerChoiceID
AND aq.ID=aac.AssessmentQuestionID
AND aq.QuestionNumber='1A'
) 1A
,(
SELECT aac.AnswerChoiceNumber
FROM AssessmentResponseAnswers ara, AssessmentAnswerChoices aac, AssessmentQuestions aq
WHERE ar.ID=ara.AssessmentResponseID
AND ara.AnswerChoiceID=aac.AnswerChoiceID
AND aq.ID=aac.AssessmentQuestionID
AND aq.QuestionNumber='1B'
) 1B
, (...)
FROM AssessmentResponses ar
WHERE ar.AssessmentID=1
AND ar.RespondentID=44
I was having problems with your usage of the joins but I tried to figure it out - maybe it is correct.