Method _setup_joins

lib/sqlalchemy/sql/selectable.py:5188–5249

(
        self,
        args: Tuple[_SetupJoinsElement, ...],
        raw_columns: List[_ColumnsClauseElement],
    )

        return [c for c in _select_iterables(statement._raw_columns)]

    def _setup_joins(
        self,
        args: Tuple[_SetupJoinsElement, ...],
        raw_columns: List[_ColumnsClauseElement],
    ) -> None:
        for right, onclause, left, flags in args:
            if TYPE_CHECKING:
                if onclause is not None:
                    assert isinstance(onclause, ColumnElement)

            explicit_left = left
            isouter = flags["isouter"]
            full = flags["full"]

            if left is None:
                (
                    left,
                    replace_from_obj_index,
                ) = self._join_determine_implicit_left_side(
                    raw_columns, left, right, onclause
                )
            else:
                replace_from_obj_index = self._join_place_explicit_left_side(
                    left
                )

            # these assertions can be made here, as if the right/onclause
            # contained ORM elements, the select() statement would have been
            # upgraded to an ORM select, and this method would not be called;
            # orm.context.ORMSelectCompileState._join() would be
            # used instead.
            if TYPE_CHECKING:
                assert isinstance(right, FromClause)
                if onclause is not None:
                    assert isinstance(onclause, ColumnElement)

            if replace_from_obj_index is not None:
                # splice into an existing element in the
                # self._from_obj list
                left_clause = self.from_clauses[replace_from_obj_index]

                if explicit_left is not None and onclause is None:
                    onclause = Join._join_condition(explicit_left, right)

                self.from_clauses = (
                    self.from_clauses[:replace_from_obj_index]
                    + (
                        Join(
                            left_clause,
                            right,
                            onclause,
                            isouter=isouter,
                            full=full,
                        ),
                    )
                    + self.from_clauses[replace_from_obj_index + 1 :]
                )
            else: