Class _ORMJoin

lib/sqlalchemy/orm/util.py:1827–1999

Extend Join to support ORM constructs as input.

class _ORMJoin(expression.Join):
    """Extend Join to support ORM constructs as input."""

    __visit_name__ = expression.Join.__visit_name__

    inherit_cache = True

    def __init__(
        self,
        left: _FromClauseArgument,
        right: _FromClauseArgument,
        onclause: Optional[_OnClauseArgument] = None,
        isouter: bool = False,
        full: bool = False,
        _left_memo: Optional[Any] = None,
        _right_memo: Optional[Any] = None,
        _extra_criteria: Tuple[ColumnElement[bool], ...] = (),
    ):
        left_info = cast(
            "Union[FromClause, _InternalEntityType[Any]]",
            inspection.inspect(left),
        )

        right_info = cast(
            "Union[FromClause, _InternalEntityType[Any]]",
            inspection.inspect(right),
        )
        adapt_to = right_info.selectable

        # used by joined eager loader
        self._left_memo = _left_memo
        self._right_memo = _right_memo

        if isinstance(onclause, attributes.QueryableAttribute):
            if TYPE_CHECKING:
                assert isinstance(
                    onclause.comparator, RelationshipProperty.Comparator
                )
            on_selectable = onclause.comparator._source_selectable()
            prop = onclause.property
            _extra_criteria += onclause._extra_criteria
        elif isinstance(onclause, MapperProperty):
            # used internally by joined eager loader...possibly not ideal
            prop = onclause
            on_selectable = prop.parent.selectable
        else:
            prop = None
            on_selectable = None

        left_selectable = left_info.selectable
        if prop:
            adapt_from: Optional[FromClause]
            if sql_util.clause_is_present(on_selectable, left_selectable):
                adapt_from = on_selectable
            else:
                assert isinstance(left_selectable, FromClause)
                adapt_from = left_selectable