SQL Server:pokročilá sestava více řádků do jednoho

K vyřešení tohoto problému můžete použít dynamické SQL - nebo pokud je to jen pro jednu sadu dat, napište je ručně. V obou případech skončíte s něčím, co vypadá takto:

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.

Tady to je, testováno a všechno.

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