# Leetcode Note: MySQL - Find Total Time Spent by Each Employee

Find Total Time Spent by Each Employee - LeetCode

https://leetcode.com/problems/find-total-time-spent-by-each-employee/

- MySQL で取り組んだメモ

## 回答

[MySolution] Group By, Two Approaches, Performance Compare - Find Total Time Spent by Each Employee - LeetCode

https://leetcode.com/problems/find-total-time-spent-by-each-employee/solutions/1086265/mysolution-group-by-two-approaches-performance-compare/

```
select
event_day as day, emp_id
, sum(out_time) - sum(in_time) as total_time
from
Employees
group by
event_day, emp_id
```