相关疑难解决方法(0)

我有两个模型：用户和组。

用户可以在一个组中，因此：

class User(db.Model):
    # other fields
    group_id = db.Column(db.Integer(), db.ForeignKey('group.id'))

但另一方面，我也会有一些有关创建该特定组的用户的信息：

class Group(db.Model):
    # other fields
    users = db.relationship("User", backref='group')
    created_by = db.Column(db.Integer(), db.ForeignKey('user.id'))

结果是：

sqlalchemy.exc.CircularDependencyError: Can't sort tables for DROP; an unresolvable foreign key dependency exists between tables: group, user.  Please ensure that the ForeignKey and ForeignKeyConstraint objects involved in the cycle have names so that they can be dropped using DROP CONSTRAINT.

我试过了use_alter=True，但它给了我：

sqlalchemy.exc.CompileError: Can't emit DROP CONSTRAINT for constraint ForeignKeyConstraint(