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