example (SQL)

-- create a table
CREATE TABLE students (
  fname char,
  lname char,
  num int
);
-- insert some values
INSERT INTO students VALUES ('sai', 'Ryan', 123);
INSERT INTO students VALUES ('pavan', 'Joanna', 456);
insert into students values('venkat', 'sujatha', 789);
insert into students values('venkat', 'sujathaaa', 780);
insert into students values(null, 'sujathaaaaa', 759);
insert into students values(null, 'sujathaa', 729);
insert into students values('venakta rao', 'sujathas', 719);
-- fetch some values
SELECT distinct fname FROM students;