basics of sql

-- create a table
CREATE TABLE students (
id INTEGER PRIMARY KEY,
name TEXT NOT NULL,
gender TEXT NOT NULL
);
-- insert some values
INSERT INTO students VALUES (1, 'Ryan', 'M');
INSERT INTO students VALUES (2, 'Joanna', 'F');
INSERT INTO students VALUES (3, 'many', 'M');
INSERT INTO students VALUES (4, 'koga', 'F');
INSERT INTO students VALUES (5, 'sammy', 'M');
INSERT INTO students VALUES (6, 'jina', 'F');
INSERT INTO students VALUES (7, 'royal', 'M');
INSERT INTO students VALUES (8, 'tamobore', 'F');
-- fetch some values
-- SELECT * FROM students ;
-- select * from students where name="many";
update students set name="Asit" where id=2;
-- select name as N,id ,gender from students where name like "A%";
Alter table students add column new varchar(225);

Alter table students modify name varchar(10);
update students set new="hi";
select * from students;

select * from students as s1,students as s2 where s1.id=s2.id ;

-- union all will not remove the duplicates remember
-- select * from students
-- union all
-- select * from students;
-- select * from students
-- union
-- select * from students;