sql - 如何使用SQL语句计算百分比(How to calculate percentage with a SQL statement)

Question

I have a SQL Server table that contains users & their grades.

(我有一个包含用户及其等级的SQL Server表。)

For simplicity's sake, lets just say there are 2 columns - name & grade .

(为了简单起见，我们只说两列name和grade 。)

So a typical row would be Name: "John Doe", Grade:"A".

(因此，典型的行是名称：“ John Doe”，等级：“ A”。)

I'm looking for one SQL statement that will find the percentages of all possible answers.

(我正在寻找一条SQL语句，该语句将找到所有可能答案的百分比。)

(A, B, C, etc...) Also, is there a way to do this without defining all possible answers (open text field - users could enter 'pass/fail', 'none', etc...)

(（A，B，C等）。此外，有没有一种方法可以定义所有可能的答案（开放文本字段-用户可以输入“通过/失败”，“无”等）。)

The final output I'm looking for is A: 5%, B: 15%, C: 40%, etc...

(我正在寻找的最终输出是A：5％，B：15％，C：40％等...)

  ask by Alex translate from so

Answer 1

I have tested the following and this does work.

(我已经测试了以下内容，这确实可行。)

The answer by gordyii was close but had the multiplication of 100 in the wrong place and had some missing parenthesis.

(gordyii的答案很接近，但是在错误的位置乘以100，并且缺少括号。)

Select Grade, (Count(Grade)* 100 / (Select Count(*) From MyTable)) as Score
From MyTable
Group By Grade