如何在sql中获得百分比？

Question

[getPollResult]

@poll_form_id int

AS
BEGIN

SELECT a.question_id,a.title,COUNT(*) vote FROM tbl_poll_option a 
JOIN tbl_poll_answer b ON a.Id=b.option_id
JOIN tbl_poll_question c ON a.question_id=c.Id
WHERE poll_form_id=@poll_form_id GROUP BY a.title,a.question_id

END

我有一个民意调查系统。我使用此查询来计算每个问题的答案。  如何获得每个回答选项的百分比如下：

  

问题1 ---＆gt; option1 = 20.13％              ---＆GT; option2 = 79.87％

     

问题2 ---＆gt; option3 = 100％

     

问题3 ---＆gt; option4 = 30％              ---＆GT; option5 = 70％

     

...

Answer 1

您可以尝试以下操作：

[getPollResult]

@poll_form_id int

AS
BEGIN

SELECT distinct a.question_id,a.title,COUNT(*) over(partition by a.question_id,a.title) / count(*) over(partition by a.question) as vote_percent
FROM tbl_poll_option a 
JOIN tbl_poll_answer b ON a.Id=b.option_id
JOIN tbl_poll_question c ON a.question_id=c.Id
WHERE poll_form_id=@poll_form_id

END