Select unique records from a table

Find unique rows from the table based on a single column and multiple columns.

Table: Employee                            

+----+-------+--------+--------------+     

| Id | Name  | Salary | DepartmentId |     

+----+-------+--------+--------------+     

| 1  | Ram   | 85000  | 1            |    

| 2  | Henry | 80000  | 2            |    

| 3  | Sam   | 60000  | 2            |    

| 4  | Shyam | 60000  | 1            |

| 5  | Ram   | 90000  | 2            |

| 6  | Shyam | 90000  | 1            |

| 7  | Leela | 80000  | 1            |

| 8  | Geeta | 70000  | 1            |

+----+-------+--------+--------------+

Unique Records based on Employee Name

+----+-------+--------+--------------+     

| Id | Name  | Salary | DepartmentId |     

+----+-------+--------+--------------+     

| 1  | Ram   | 85000  | 1            |    

| 2  | Henry | 80000  | 2            |    

| 3  | Sam   | 60000  | 2            |    

| 4  | Shyam | 60000  | 1            |

| 7  | Leela | 80000  | 1            |

| 8  | Geeta | 70000  | 1            |

+----+-------+--------+--------------+

Unique Records based on Employee

Name and DepartmentId

+----+-------+--------+--------------+     

| Id | Name  | Salary | DepartmentId |     

+----+-------+--------+--------------+     

| 1  | Ram   | 85000  | 1            |    

| 2  | Henry | 80000  | 2            |    

| 3  | Sam   | 60000  | 2            |    

| 4  | Shyam | 60000  | 1            |

| 5  | Ram   | 90000  | 2            |

| 7  | Leela | 80000  | 1            |

| 8  | Geeta | 70000  | 1            |

+----+-------+--------+--------------+

Approach:

Mysql

// Unique based on name only

Select Id, Name, Salary, DepartmentId 

from Employee GROUP BY Name;

// Unique based on name and department

Select Id, Name, Salary, DepartmentId 

from Employee GROUP BY Name, 

DepartmentId;

Oracle

// Unique based on name only

Select Id, Name, Salary, DepartmentId 

from Employee GROUP BY Name;

// Unique based on name and department

Select Id, Name, Salary, DepartmentId 

from Employee 

GROUP BY Name, DepartmentId;