It's very easy to fetch Top N records from DB but in a different ways.
For ex:-
1). SQL-Server-> Top clause is used for fetching N records in ascending or descending order.
For Ex:-
Select Top 20 Employee_id,Employee_name,Employee_code,address from employee_master where status = 'AA';
2). Oracle -> RowNum clause is used.
For Ex:-
Select Employee_id,Employee_name,Employee_code,address from employee_master where status = 'AA' and RowNum <= 20;
3). MySql -> Limit clause is used.
For Ex:-
Select Employee_id,Employee_name,Employee_code,address from employee_master where status = 'AA' order by Employee_name,Employee_code asc Limit 20;
4). DB2 -> Fetch First N Rows Only is used.
For Ex:-
Select Employee_id,Employee_name,Employee_code,address from employee_master where status = 'AA' order by Employee_name,Employee_code asc
Fetch First 20 Rows Only;
5). PostgreSql DB -> Limit as well as Offset clause is used.
For Ex:-
Select Employee_id,Employee_name,Employee_code,address from employee_master where status = 'AA' order by Employee_name,Employee_code asc
Limit 10 Offset 20;
Note:- In Offset case,it will skip the row from 1 to 19 and return the record from 20th to 30th record.