$user=M('user');1: SELECT * FROM user----------$user->select();2: SELECT* FORM user WHERE id=2---------$user->find(2);3: SELECT username FORMuser-----$user->field('username')->select();
4: DELETE FORM username WHEREid=2------$user->delete(2);
5: UPDATE user SET username='newUsername' WHERE id=2-------$data['username']='newUsername' $user->save($data);
6: INSERT INTO user (name,password)VALUES('php','phpPwd')------$data['name']='php' $data['password']='phpPwd'  $user->add($data);