class Event(Base):
    id = sa.Column(sa.Integer, primary_key=True, index=True)
    owner_id = sa.Column(
        sa.Integer,
        sa.ForeignKey('users.id'),
        nullable=True
    )
    owner = relationship('User', back_populates='event')

    members: Mapped[List["UserEventAssociation"]] = relationship(
        back_populates='events',
    )
    address: Mapped["Address"] = relationship(
        uselist=False,
        back_populates='event',
    )

class User(Base):
    event = relationship('Event', back_populates='owner')


class Address(Base):
    event_id: Mapped[int] = mapped_column(
        sa.Integer,
        sa.ForeignKey('events.id'),
        nullable=False
    )
    event: Mapped["Event"] = relationship(
        back_populates='address',
        uselist=False
    )