[MySolution] Group two things (faster than 97.08%)
SELECT event_day as day,emp_id,SUM(out_time-in_time) as total_time\nFROM Employees\nGROUP BY event_day,emp_id
SELECT event_day as day,emp_id,SUM(out_time-in_time) as total_time\nFROM Employees\nGROUP BY event_day,emp_id
['MySQL']