✅MySQL || GROUP BY and SUM() aggregate function
\n\n\n\tSELECT event_day AS day, emp_id, sum(out_time-in_time) AS total_time \n\tFROM employees GROUP BY event_day,emp_id;\n
![image](https://assets.leetcode.com/users/images/332dbbfb-ed2d-4834-b5a6-bcfed7060055_1673884982.170401.png)\n\n\n\tSELECT event_day AS day, emp_id, sum(out_time-in_time) AS total_time \n\tFROM employees GROUP BY event_day,emp_id;\n
['MySQL']