Method _sorted_tables

lib/sqlalchemy/orm/mapper.py:4007–4055

(self)

    @HasMemoized.memoized_attribute
    def _sorted_tables(self):
        table_to_mapper: Dict[TableClause, Mapper[Any]] = {}

        for mapper in self.base_mapper.self_and_descendants:
            for t in mapper.tables:
                table_to_mapper.setdefault(t, mapper)

        extra_dependencies = []
        for table, mapper in table_to_mapper.items():
            super_ = mapper.inherits
            if super_:
                extra_dependencies.extend(
                    [(super_table, table) for super_table in super_.tables]
                )

        def skip(fk):
            # attempt to skip dependencies that are not
            # significant to the inheritance chain
            # for two tables that are related by inheritance.
            # while that dependency may be important, it's technically
            # not what we mean to sort on here.
            parent = table_to_mapper.get(fk.parent.table)
            dep = table_to_mapper.get(fk.column.table)
            if (
                parent is not None
                and dep is not None
                and dep is not parent
                and dep.inherit_condition is not None
            ):
                cols = set(sql_util._find_columns(dep.inherit_condition))
                if parent.inherit_condition is not None:
                    cols = cols.union(
                        sql_util._find_columns(parent.inherit_condition)
                    )
                    return fk.parent not in cols and fk.column not in cols
                else:
                    return fk.parent not in cols
            return False

        sorted_ = sql_util.sort_tables(
            table_to_mapper,
            skip_fn=skip,
            extra_dependencies=extra_dependencies,
        )

        ret = util.OrderedDict()
        for t in sorted_:
            ret[t] = table_to_mapper[t]
        return ret

    def _memo(self, key: Any, callable_: Callable[[], _T]) -> _T:
        if key in self._memoized_values: