Hi all, We have a list of polymorphic objects from which delete object does not work, not matter what we try. The situation:
class ItemGroup(Base): __tablename__ = 'item_group' __table_args__ = ( UniqueConstraint('model_id', 'item_group_color_id', name='unique_model_id_item_group_color_id_uc'), ) id = Column(Integer, primary_key=True) items = relationship("Item", back_populates="item_group") class Item(Base): __tablename__ = 'item' id = Column(Integer, primary_key=True) item_group_id = Column(ForeignKey('item_group.id'), nullable=False, index=True) item_group = relationship('ItemGroup', back_populates="items", uselist=False) __mapper_args__ = { 'polymorphic_identity': __tablename__, 'polymorphic_on': item_type } class ItemMeta(Item): __tablename__ = 'item_meta' id = Column(Integer, ForeignKey('item.id', ondelete="CASCADE"), primary_key=True) meta_name = Column(String(255, collation), nullable=False) __mapper_args__ = { 'polymorphic_identity': __tablename__, } The problem occurs after a delete: session.query(ItemMeta).filter_by(item_group=ig).delete() Now, querying the child works fine: session.query(ItemMeta).filter_by(item_group=ig).all() [] But querying the parent: test_fixtures.session.query(Item).filter_by(item_group=ig).all() Give: Instance '<ItemMeta at 0x7f0b024afcf8>' has been deleted, or its row is otherwise not present. In the database I can see the lingering parent objects. I guess that I have to use something like delete-orphan, but as I dont have a relation from child to father, so now I'm stuck. Any ideas are welcome. Kind regards, Nacho -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sqlalchemy/7dea2eaa-6390-4a54-abd5-fae925727c17%40googlegroups.com.