flask sqlalchemy initial database code example

Example: flask sqlalchemy initial database

db = SQLAlchemy(app)class students(db.Model):   id = db.Column('student_id', db.Integer, primary_key = True)   name = db.Column(db.String(100))   city = db.Column(db.String(50))     addr = db.Column(db.String(200))   pin = db.Column(db.String(10))def __init__(self, name, city, addr,pin):   self.name = name   self.city = city   self.addr = addr   self.pin = pin