MySQL Calculate Percentage

Question

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

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

This is the statement I have now:

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:

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 employees who by the number in surveys have taken the survey. i.e. as shown in the data above, the Awesome Group A would be 0% and Awesome Group B would be 95%.

Answer 1

try this

   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