SQL Server: advanced report of multiple rows into

Question

I have code that puts together data from many tables regarding a users response to all questions of a specific lesson. Responses look like this:

userid|lesson|question |response|label|weight|duration_seconds
========================================================================
bob   |first |loc_nameA|4       |R9   |3.5   |189
bob   |first |loc_nameB|2       |R7   |4.5   |113
…

A report needs to be made showing all responses shown in one row. So for each question I need to display the response into a column along with its corresponding label,weight and duration like this:

userid|lesson|1_resp|1_labl|1_weig|1_dura|2_resp|3_labl|3_weig|3_dura|4_resp…
========================================================================
bob   |first |4     |R9    |3.5   |189   |2     |R7    |4.5   |113   |1

OR alternatively by using the "question" column value as part of the dynamic column name. Currently they all have logical names like L1Q1 so just 1,2,3 will suffice as column names, but this might not always be the case:

userid|lesson|loc_nameA_resp|loc_nameA_labl|loc_nameA_weig|loc_nameA_dura|loc_nameB_resp|loc_nameB_labl|loc_nameB_weig|loc_nameB_dura|loc_nameC_resp…
================================================================================================================================================
bob   |first |4             |R9            |3.5           |189           |2             |R7            |4.5           |113           |1

I have been reading about pivot tables but all examples seem more limited than what I am describing. How can this be done with SQL Server 2005? Should I be using something else? Is there an easier way?

Answer 1

You can use dynamic SQL to solve this problem -- or if it is just for one set of data write it by hand. In both cases you are going to end up with something that looks like this:

SELECT R1.userid, R1.lesson, 
       R1.response as loc_nameA_resp, R1.lable as loc_nameA_labl, R1.weight as loc_nameA_weig, R1.duration_seconds as loc_nameA_dura,
       R2.response as loc_nameB_resp, R2.lable as loc_nameB_labl, R2.weight as loc_nameB_weig, R2.duration_seconds as loc_nameB_dura,
--- etc for each question
FROM user U
JOIN response R1 on R1.userid = u.userid and R1.lesson = 'first' and R1.question = 'loc_nameA'
JOIN response R2 on R2.userid = u.userid and R2.lesson = 'first' and R2.question = 'loc_nameB'
--- etc for each question
WHERE
   U.userid = 'bob' -- this does not need to be bob, whatever user you want.

---

Here you go, tested and everything.

DECLARE @sqlSelectList varchar(max);
DECLARE @sqlJoinList varchar(max);

SELECT @sqlSelectList = '', @sqlJoinList='';

WITH Questions AS
(
  SELECT DISTINCT question
  FROM ResultsChoices
)
SELECT -- We use the question as the alias for join uniqueness,
       -- We could increment a number but why bother?
  @sqlJoinList = @sqlJoinList +
     ' JOIN ResultsChoices '+question+' on '+question+'.userid = u.userid and '+question+'.question = '''+question+'''', 
  @sqlSelectList = @sqlSelectList +
     ', '+question+'.response as '+question+'_resp, '+question+'.label as '+question+'_labl, '+question+'.weight as '+question+'_weig, '+question+'.duration_seconds as '+question+'_dura '
FROM Questions;

DECLARE @sql NVARCHAR(max);

SET @sql = N'SELECT DISTINCT u.userid ' + @sqlSelectList + N' FROM #ResultsChoices u ' + @sqlJoinList;

EXEC sp_executesql @sql