Flask SQLAlchemy 邻接表关系¶

Question

I am trying to set up a table that should include a foreign key that points to the table itself just like a tree with nodes and therefore a parent and children.

I followed the example on https://docs.sqlalchemy.org/en/14/orm/self_referential.html which looks like the following

class Node(Base):
    __tablename__ = 'node'
    id = Column(Integer, primary_key=True)
    parent_id = Column(Integer, ForeignKey('node.id'))
    data = Column(String(50))
    children = relationship("Node")

When implementing this class in Flask I get the following error:

The foreign key associated with column 'node.parent_id' could not find table 'node' with which to generate a foreign key to target column 'id'.

Any ideas on how to fix it?

Thanks in advance

Answer 1

My understanding is the relationship("something") looks for the class with tablename = "something" (not the class name). See if changing it to children = relationship("node") works