从Parent.children中删除一对多关系中的Child，但保留child.parent_id

Question

我有与"Basic Relationship Pattern One-To-Many" in the SQLAlchemy documentation.

类似的父表和子表

class Parent(Base):
    __tablename__ = 'parent'
    id = Column(Integer, primary_key=True)
    children = relationship("Child", back_populates="parent")

class Child(Base):
    __tablename__ = 'child'
    id = Column(Integer, primary_key=True)
    parent_id = Column(Integer, ForeignKey('parent.id'))
    parent = relationship("Parent", back_populates="children")

我想从Child中移除Parent，但请将child.parent_id设置为原始父级。

>>> parent = Parent()
>>> child = Child()
>>> parent.children.append(child)
>>> db.session.commit()
>>> assert child.parent_id == 1
>>> parent.children.remove(child)
>>> db.session.commit()
>>> assert len(parent.children) == 0
>>> assert child.parent_id == 1

这可以在不修改这些表的列的情况下实现吗？