組選擇一些領域的價值

Question

有我一個下列選擇：

| EmployeeId | DepartmentName | Salary | 
---------------------------------------- 
| 1   | A    | 10  | 
| 2   | A    | 10  | 
| 3   | A    | 15  | 
| 4   | A    | 20  | 
| 5   | A    | 20  | 
| 6   | B    | 15  | 
| 7   | B    | 25  | 
| 8   | B    | 25  | 

我想按工資所有行每個部門，這一數字組添加到選擇。結果選擇的

例子：

| EmployeeId | DepartmentName | Salary | Group | 
------------------------------------------------ 
| 1   | A    | 10  | 1  | 
| 2   | A    | 10  | 1  | 
| 3   | A    | 15  | 2  | 
| 4   | A    | 20  | 3  | 
| 5   | A    | 20  | 3  | 
| 6   | B    | 15  | 1  | 
| 7   | B    | 25  | 2  | 
| 8   | B    | 25  | 2  | 

Answer 1

SELECT * 
     , DENSE_RANK() OVER (PARTITION BY DepartmentName 
          ORDER BY Salary) AS [Group] 
FROM TableName