MySQL MySQL计算百分比

MySQL Calculate Percentage

提问by user2232709

I have a MySQL database with 4 items: id(numerical), group_name, employees, and surveys.

我有一个包含 4 个项目的 MySQL 数据库：（id数字）group_name、employees、 和surveys。

In my SELECTI need to calculate the percentage of 'employees' who, by the number in 'surveys', have taken the survey.

在我SELECT我需要计算谁，在“调查”的数量，所采取的调查，“雇员”的百分比。

This is the statement I have now:

这是我现在的声明：

SELECT
  group_name,
  employees,
  surveys,
  COUNT( surveys ) AS test1, 
  ((COUNT( * ) / ( SELECT COUNT( * ) FROM a_test)) * 100 ) AS percentage
FROM
  a_test
GROUP BY
  employees

Here is the table as it stands:

这是它的表格：

INSERT INTO a_test (id, group_name, employees, surveys) VALUES
(1, 'Awesome Group A', '100', '0'),
(2, 'Awesome Group B', '200', '190'),
(3, 'Awesome Group C', '300', '290');

I would love to calculate the percentage of employeeswho by the number in surveyshave taken the survey. i.e. as shown in the data above, the Awesome Group Awould be 0% and Awesome Group Bwould be 95%.

我很想employees通过surveys参加调查的人数来计算谁的百分比。即如上面的数据所示，Awesome Group A将是 0% 和Awesome Group B95%。

回答by echo_Me

try this

尝试这个

   SELECT group_name, employees, surveys, COUNT( surveys ) AS test1, 
        concat(round(( surveys/employees * 100 ),2),'%') AS percentage
    FROM a_test
    GROUP BY employees

DEMO HERE

演示在这里