sql table, students example 2/1/17
//Example of creating a table//
CREATE TABLE students(
id INTEGER(11) AUTO_INCREMENT NOT NULL, //INTEGER = number
name VARCHAR(30) NOT NULL, //VARCHAR = letter or 'strings'
age INTEGER(10),
location VARCHAR(30) NOT NULL,
PRIMARY KEY(id) *****//Very IMportant, always want to assign id's to everything********
);
INSERT INTO <table name> (column names) VAlues(value for each column)
select * , selects all columns
select * from //to from certain row//
select * from students where id in (2,3);
//to update //
UPDATE students SET name = 'JHON' WHERE id = 2;///specify where or everything deletes;///
//TO UPDATE TWO IDS//
UPDATE students SET age=22 where id in (3,4);
ACD --> Add Change Delete
//to delete//
DELETE from students
WHERE id=4;
select * from students left join pets on pets.student_id = students.id; //or//
select * from students s left join pets p on s.id = p.student_id; //shows all the students first and joing pets to the table//
" " " s right join pets p on s.id = p.students_id //grabs everything from the right table and joins everything to the left table//
ALTER TABLE pets
-> ADD FOREIGN KEY (student_id)
-> REFERENCES students(id);
this is to add the foreign key