MySQL计算百分比

Question

我有4个项目MySQL数据库:id(数值)group_name,employees和surveys.

在我看来,SELECT我需要根据"调查"中的数字来计算"员工"的百分比.

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

这是表格:

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');

我很想计算参与调查employees的人数百分比surveys.即,如上面的数据所示,Awesome Group A它将是0%并且Awesome Group B将是95%.

Answer 1

试试这个

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

在这里演示