1741. Find Total Time Spent by Each Employee
```\nSELECT event_day AS day, emp_id, \nSUM(out_time) - SUM(in_time) AS total_time\nFROM employees\nGROUP BY emp_id, day ;
```\nSELECT event_day AS day, emp_id, \nSUM(out_time) - SUM(in_time) AS total_time\nFROM employees\nGROUP BY emp_id, day ;
['MySQL']