Write a SQL Program to Select every Nth record.

CREATE TABLE student(id int, name varchar(30), age int, gender char(6));

INSERT INTO student VALUES
    (1 ,'Ranga', 27, 'Male'),
    (2 ,'Reddy', 26, 'Male'),
    (3 ,'Vasu',  50, 'Female'),
    (4 ,'Ranga', 27, 'Male'),
    (5 ,'Raja', 10, 'Male'),
    (6 ,'Pavi',  52, 'Female'),
    (7 ,'Vinod', 27, 'Male'),
    (8 ,'Vasu',  50, 'Female'),
    (9 ,'Ranga', 27, 'Male'),
    (10 ,null, 27, 'Male');

Program:
-----------------------------------------------
SELECT * FROM (
    SELECT @row := @row +1 AS Rownum, name as Name FROM (SELECT @row :=0) r, student
) students
WHERE rownum %3 = 1;

Output:
-----------------------------------------------
Rownum  Name
1       Ranga
4       Ranga
7       Vinod
10      (null)