Oracle function： row_number()
1. select * from (select * from (select t.*, row_number() OVER(ORDER BY null) AS "row_number" from twitter_accounts t) p where p."row_number" > 0 and p."row_number" <=2) q where rownum <= 10 2. SELECT department_id, last_name, employee_id, ROW_NUMBER() OVER ( PARTITION BY department_id ORDER BY employee_id) AS emp_id FROM employees; 3. SELECT last_name FROM (SELECT last_name, ROW_NUMBER() over (order by last_name ) R FROM employees) WHERE R BETWEEN 51 and 100;