How to select a row based on its row number?

Question

I\'m working on a small project in which I\'ll need to select a record from a temporary table based on the actual row number of the record.

How can I select a record

Answer 1

There are 3 ways of doing this.

Suppose u have an employee table with the columns as emp_id, emp_name, salary. You need the top 10 employees who has highest salary.

1. Using row_number() analytic function

   Select * from
   ( select emp_id,emp_name,row_number() over (order by salary desc) rank
   from employee)
   where rank<=10
   

2. Using rank() analytic function

   Select * from
   ( select emp_id,emp_name,rank() over (order by salary desc) rank
   from employee)
   where rank<=10
   

3. Using rownum

   select * from
   (select * from employee order by salary desc)
   where rownum<=10;