Class B

test/orm/test_dynamic.py:1559–1568

                )

            class B(decl_base):
                __tablename__ = "b"
                id: Mapped[int] = mapped_column(Identity(), primary_key=True)
                a_id: Mapped[int] = mapped_column(
                    ForeignKey(
                        "a.id",
                        ondelete="cascade" if cascade_deletes else "set null",
                    ),
                    nullable=not cascade_deletes,
                )

            decl_base.metadata.create_all(connection)
            return A, B