class teacher(db.Model): id = db.Column(db.String(10), primary_key=True) name = db.Column(db.String(20), nullable=False) tbrelation = db.relationship('borrow', backref='tname', lazy=True) def __repr__(self): return f"Teacher('{self.name}','{self.id}')"
class history(db.Model): sid = db.Column(db.String(10), nullable=False, primary_key=True) bid = db.Column(db.String(10), db.ForeignKey('books.id'), nullable=False, primary_key=True) date_given = db.Column(db.DateTime, nullable=False, primary_key=True) date_returned = db.Column(db.DateTime, nullable=False, default=date.today()) penalty = db.Column(db.Integer, default=0) def __repr__(self): return f"history('{self.sid}','{self.bid}','{self.date_given}','{self.date_returned}','{self.penalty}')"
class books(db.Model): id = db.Column(db.String(10), primary_key=True) bname = db.Column(db.String(100), nullable=False) date = db.Column(db.String(20), nullable=False) author = db.Column(db.String(50), nullable=False) publisher = db.Column(db.String(50), nullable=False) place = db.Column(db.String(50), nullable=False) year = db.Column(db.String(20), nullable=False) edvol = db.Column(db.String(50), nullable=False) pages = db.Column(db.String(10), nullable=False) cost = db.Column(db.String(10), nullable=False) orderno = db.Column(db.String(10), nullable=False) supplier = db.Column(db.String(50), nullable=False) classno = db.Column(db.String(10), nullable=False) borrower = db.relationship('borrow', backref='book_name', lazy=True) back_history = db.relationship('history', backref='book', lazy=True) def __repr__(self): return f"Book('{self.id}','{self.bname}')"