I have a self referential polymorphic relationship using single table inheritance
Base = declarative_base() class Item(Base): __tablename__ = 'item' id = Column(Integer) type = Column(String) __mapper_args__ = { 'polymorphic_on': type, 'with_polymorphic': '*'} class Food(Item): calories = Column(Integer) __mapper_args__ = {'polymorphic_identity': 'food'} class Book(Item): pages = Column(Integer) __mapper_args__ = {'polymorphic_identity': 'book'} class Toy(Item): rating = Column(Integer) __mapper_args__ = {'polymorphic_identity': 'toy'} class BasetPiece(Base): __tablename__ = 'basket_piece' basket_id = Column(Integer, ...) piece_id = Column(Integer, ...) quantity = Column(Integer) class Basket(Item): items = relationship() __mapper_args__ = {'polymorphic_identity': 'food'} So I need to essentially select all food with > 100 calories, books with < 500 pages, and baskets which contain either, in one query. SELECT * FROM item i LEFT OUTER JOIN basket_piece bp ON bp.basket_id = i.id LEFT OUTER JOIN item p ON p.id = bp.piece_id WHERE i.calories > 100 OR i.pages < 500 OR p.calories > 100 OR p.pages < 500; But I can't figure out how to do this in sqlalchemy because the columns of the subclasses are not attributes of the Item class. Piece = aliased(Item) session.query(Item).outerjoin(BasketPiece).outerjoin(Piece).filter(sa.or_(Item.calories > 100, Item.pages < 500, Piece.calories > 100, Piece.pages < 500)).all() How do I acheieve this? -- 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 post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.