Say I have a Question which belongs to some Homework. A Question can be correctly answered, and Homework is passed if all Questions are correct. class Question(Base): __tablename__ = 'questions' id: Mapped[int] = mapped_column(primary_key=True) answered_correctly: Mapped["bool"] = mapped_column() homework: Mapped["Homework"] = relationship(back_populates="questions") homework_id: Mapped[int] = mapped_column(ForeignKey("homework.id")) class Homework(Base): __tablename__ = 'homework' id: Mapped[int] = mapped_column(primary_key=True) answered_correctly: Mapped["bool"] = mapped_column() questions: Mapped[list["Questions"]] = relationship( back_populates="homework", default_factory=list ) @hybrid_property def passed(self): return all([question.answered correctly for question in self.questions]) How do I get this to work in an SQL query? I know that I have to implement passed.expression, but I'm unclear on what exactly it should return. I have an SQL query that I can use to find homework that isn't passed - do I have to translate this query to SQLAlchemy's API, & that's what passed.expression is supposed to return? SELECT homework.id, from homework JOIN question on question.id = homework.id WHERE homework.id = &1 GROUP BY homework.id HAVING COUNT(CASE WHEN question.answered_correctly = FALSE THEN 1 END) > 0 Continue reading...
