Duplicate values in the table.

Please use this commands in your sql prompt.

• select salary from employees

now observethe results, you will notice many rows are not unique, some of them are same, hence we getsome duplicate values also, there may be situation where you need only unique values. For this kind of situations please use a keyword called Distinct.

• Distinct keyword in oracle sql will eliminate the duplicates in oracle.

please use the below query to eliminate dupicates when you query department_id

• Select distinct department_id from employees.