Complete Code

import sqlite3
class Database :
    def __init__(self):
      self.connection = sqlite3.connect('school.db')
      self.cursor = self.connection.cursor()

    def create_table(self,query):
     self.cursor.execute(query) 


class Student:
  name = ''
  email = ''
  phone = ''

  def __init__(self):
    self.db = Database()

  def insert_student(self):
    sql = 'INSERT INTO students (name,email,phone) values (?,?,?)'
    values = (self.name,self.email,self.phone)
    self.db.cursor.execute(sql,values)
    self.db.connection.commit()

  def get_all_students(self):
   sql = 'SELECT id, name, email, phone FROM students'
   self.db.cursor.execute(sql)    
   return self.db.cursor.fetchall()  
  
  def get_student(self,student_id):
   self.db.cursor.execute('SELECT id,NAME,EMAIL,PHONE from students WHERE id = ?',(student_id,))
   return self.db.cursor.fetchone()
  def update_student(self,id):
   self.db.cursor.execute('UPDATE students set name =?,email=?,phone=? WHERE id = ?',(self.name,self.email,self.phone,id))
   self.db.connection.commit()

  def delete_student(self,id):
   self.db.cursor.execute('DELETE FROM students WHERE id = ?',(id,)) 
   self.db.connection.commit()