Method setup_mappers

test/orm/test_composites.py:1307–1350

(cls)

    @classmethod
    def setup_mappers(cls):
        values, descriptions = cls.tables.values, cls.tables.descriptions

        class Descriptions(cls.Comparable):
            pass

        class Values(cls.Comparable):
            pass

        class CustomValues(cls.Comparable, list):
            def __init__(self, *args):
                self.extend(args)

            def __composite_values__(self):
                return self

        desc_values = (
            select(values, descriptions.c.d1, descriptions.c.d2)
            .where(
                descriptions.c.id == values.c.description_id,
            )
            .alias("descriptions_values")
        )

        cls.mapper_registry.map_imperatively(
            Descriptions,
            descriptions,
            properties={
                "values": relationship(Values, lazy="dynamic"),
                "custom_descriptions": composite(
                    CustomValues, descriptions.c.d1, descriptions.c.d2
                ),
            },
        )

        cls.mapper_registry.map_imperatively(
            Values,
            desc_values,
            properties={
                "custom_values": composite(
                    CustomValues, desc_values.c.v1, desc_values.c.v2
                )
            },
        )

    def test_set_composite_attrs_via_selectable(self, connection):
        Values, CustomValues, values, Descriptions, descriptions = (