How to Limit Sql Query result in MS SQL, My SQL, Postgres, Oracle Database?

SQL SELECT TOP, LIMIT, ROWNUM - In a Query

Recently in one of the interviews I was asked how to Limit SQL Query result in MS SQL, My SQL, Postgres, Oracle Database. For example I have a table named employee in my database so find the query example below in different databases :-

In MS SQL (Using top)

Example 1: Returning first 50 rows from a table:
select top 50 * from employee

Example 2: Returning top 10% of rows from a table
select top 10 percent * from employee



In MySQL (Using limit)

Example 1: Returning the first 100 rows from a table
select * from employee limit 100

Example 2: Returning a range of rows from a table (starting at record 2, return the next 4 rows)
select * from employee limit 2,4


In PostGres (Using limit)

Example 1: Returning the first 100 rows from a table
select * from employee limit 100

Example 2: Returning 10 records from the table employee starting at row 3
select * from employee limit 10 offset 3

 
In Oracle (Using rownum)

Example 1: Returning the first 100 rows from a table
select * from employee where rownum <= 100

Example 2: Returning the first 100 rows in order of salary from a table
select * from (select * from employee order by salary desc) where rownum <= 100

Note: that the rownum query has to be wrapped around an inner select that actually does the order by.