+------------+--------+-----------+---------------+
| paydate | salary | ninumber | payrollnumber |
+------------+--------+-----------+---------------+
| 2015-05-15 | 1000 | jh330954b | 6 |
| 2015-04-15 | 1250 | jh330954b | 5 |
| 2015-03-15 | 800 | jh330954b | 4 |
| 2015-02-15 | 894 | jh330954b | 3 |
| 2015-05-15 | 500 | ew56780e | 6 |
| 2015-04-15 | 1500 | ew56780e | 5 |
| 2015-03-15 | 2500 | ew56780e | 4 |
| 2015-02-15 | 3000 | ew56780e …