MySQL | SIMPLE
\nSELECT event_day as day,emp_id,SUM(out_time - in_time) AS total_time\nFROM employees\nGROUP BY day,emp_ida\n
```\nSELECT event_day as day,emp_id,SUM(out_time - in_time) AS total_time\nFROM employees\nGROUP BY day,emp_ida\n```
['MySQL']