Method _table_to_equated

lib/sqlalchemy/orm/mapper.py:4093–4122

memoized map of tables to collections of columns to be synchronized upwards to the base mapper.

(self)

    @util.memoized_property
    def _table_to_equated(self):
        """memoized map of tables to collections of columns to be
        synchronized upwards to the base mapper."""

        result: util.defaultdict[
            Table,
            List[
                Tuple[
                    Mapper[Any],
                    List[Tuple[ColumnElement[Any], ColumnElement[Any]]],
                ]
            ],
        ] = util.defaultdict(list)

        def set_union(x, y):
            return x.union(y)

        for table in self._sorted_tables:
            cols = set(table.c)

            for m in self.iterate_to_root():
                if m._inherits_equated_pairs and cols.intersection(
                    reduce(
                        set_union,
                        [l.proxy_set for l, r in m._inherits_equated_pairs],
                    )
                ):
                    result[table].append((m, m._inherits_equated_pairs))

        return result


class _OptGetColumnsNotAvailable(Exception):