create view from multiple row into one row

Question

i have two table; question and answer

question table

QuestionID QuestionText
1          Question1
2          Question2
3          Question3

answer table. where it has fk to question table and bit to determine whether the answer is right

answerID answer_question_id(fk) answertxt answer_isright
1          1                    answer1   1
2          1                    answer2   0
3          1                    answer3   0
4          2                    answer1   1
5          2                    answer2   0
6          2                    answer3   0

so how do i create view where the first column is the question and second,third and fourth column is the answers (randomly)?

Answer 1

You can use PIVOT to solve your problem:

SELECT questionText, [1], [2], [3]
FROM
(
    SELECT 
        ROW_NUMBER() OVER (PARTITION BY QuestionID ORDER BY newid()) AnswerInQuestionID,
        answerTxt, 
        QuestionText
    FROM questions q
        JOIN answers a
            ON q.QuestionID=a.answer_question_id
) A
PIVOT
(
    MAX(answerTxt)
    FOR AnswerInQuestionID IN ([1], [2], [3] )
) as piv

SQL FIDDLE DEMO

Answer 2

next query

SELECT answerid, answer_question_id, answer_isright, 
row_number() over (partition by answer_question_id order by newid()) as rnum
from answers

will return you your answer table with extra column to represent what column that answer goes to. "order by newid()" is not part of a standard and is different for every database vendor.

answerId  .... rnum
1              1    
2              3
3              2    
4              3
5              1    
6              2

(rnums would be different for every execution)

then you use this query to move answers to different columns based on rnum

select answerid, ..., case when rnum = 1 then answertxt else null end co1, ...

this will move your text like this:

answerId  .... rnum ... col1,   col2   col3
1              1        text1   null   null
2              3        null    null   text2
3              2        null    text3  null
4              3        null    null   text4
5              1        text5   null   null
6              2        null    text6  null

then you need to group them:

select answer_question_id, .., max(col1), max(col2), max(col3) from prev_query
group by answer_question_id, ...

then you join with a questions to add question text