小编Chr*_*the的帖子

我是新使用 sqlAlchemy 并且在创建新表时遇到问题，特别是当它有 2 个外键指向 1 个表时：

class Offers(db.Model):
    __tablename__ = 'offers'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    contact_ign = db.Column(db.String(100))
    conversion_rate = db.Column(db.Float)
    stock = db.Column(db.Integer)
    create_date = db.Column(db.DateTime(timezone=True), default=func.now())
    currency_pair = db.relationship('CurrencyPairs', backref='pair', lazy='dynamic')

class CurrencyPairs(db.Model):
    __tablename__ = 'currency_pairs'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    league = db.Column(db.String(100))
    pair_id = db.Column(db.Integer, db.ForeignKey('offers.id'))
    want = db.relationship('Currency', backref='want', lazy='dynamic')
    have = db.relationship('Currency', backref='have', lazy='dynamic')

class Currency(db.Model):
    __tablename__ = 'currency'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    name = db.Column(db.String(100), nullable=False)
    poe_trade = db.Column(db.Integer, nullable=False) …