如何将2列转置为行

Question

我目前有这个用于调查的表，我只需要对问题No3的回答和评论的评论以及对问题No4的评论

+---------------------------------------------------+
| Employee | SurveyNo | Question | Answer | Comment |
+----------+----------+----------+--------+---------+
|   100    |    1     |    1     |Neutral |   NULL  |
|   100    |    1     |    2     |  Hard  |   NULL  |
|   100    |    1     |    3     |  Easy  |  asdfs  |
|   100    |    1     |    4     |  NULL  |  ssafa  |
|   200    |    2     |    1     |  Hard  |   NULL  |
|   200    |    2     |    2     |  Hard  |   NULL  |
|   200    |    2     |    3     |  Easy  |  asdfs  |
|   200    |    2     |    4     |  NULL  |   NULL  |
+---------------------------------------------------+

我正在寻找的是这样的

+--------------------------------------------------------------------------------+
| Employee | surveyNo |Question1 | Question2 | Question3 | CommentsQ3 | Comments |
+----------+----------+----------+-----------+-----------+------------+----------+
|   100    |    1     | Neutral  |    Hard   |   Easy    |   asdfs    |  ssafa   |
|   200    |    2     |   Hard   |    Hard   |   Easy    |   asdfs    |          |
+--------------------------------------------------------------------------------+

目前我可以得到每个问题而不是评论，我只想要问题3的评论和问题4的评论。

但是当我包含评论时，我开始获得重复的行

SELECT  Employee,surveyNo,[1] as Question1,[2] as Question2,[3] as Question3
FROM
(
SELECT Employee,surveyNo,answer FROM Surveys WHERE Question in (1,2,3)
) d
pivot
(
max(answer)
for Question in ([1],[2],[3])
) piv

+--------------------------------------------------------+
| Employee | surveyNo |Question1 | Question2 | Question3 | 
+----------+----------+----------+-----------+-----------+
|   100    |    1     | Neutral  |    Hard   |   Easy    |
|   200    |    2     |   Hard   |    Hard   |   Easy    |
+--------------------------------------------------------+

Answer 1

你可以做条件聚合：

SELECT Employee, surveyNo,
       MAX(CASE WHEN Question = 1 THEN Answer END) AS Question1 ,
       . . . 
       MAX(CASE WHEN Question = 1 THEN Comment END) AS CommentsQ1,
       . . .
FROM Surveys 
WHERE Question in (1,2,3)
GROUP BY Employee, surveyNo;