调试中...
Salary =
| id | employee_id | amount | pay_date |
| -- | ----------- | ------ | ---------- |
| 1 | 1 | 9000 | 2017/03/31 |
| 2 | 2 | 6000 | 2017/03/31 |
| 3 | 3 | 10000 | 2017/03/31 |
| 4 | 1 | 7000 | 2017/02/28 |
| 5 | 2 | 6000 | 2017/02/28 |
| 6 | 3 | 8000 | 2017/02/28 |
Employee =
| employee_id | department_id |
| ----------- | ------------- |
| 1 | 1 |
| 2 | 2 |
| 3 | 2 |
[object Object]