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| totalSalary | nextTotalSalary | ( case when isnull(r.nextTotalSalary)= 1 then r.totalSalary else nextTotalSalary end ) - r.totalSalary |
|---|---|---|
| 10000 | 12000 | 2000 |
| 12000 | 15000 | 3000 |
| 15000 | null | 0 |