Class FromStatement

lib/sqlalchemy/orm/context.py:961–1078

Core construct that represents a load of ORM objects from various :class:`.ReturnsRows` and other classes including: :class:`.Select`, :class:`.TextClause`, :class:`.TextualSelect`, :class:`.CompoundSelect`, :class`.Insert`, :class:`.Update`, and in theory, :class:`.Delete`.

class FromStatement(GroupedElement, Generative, TypedReturnsRows[Unpack[_Ts]]):
    """Core construct that represents a load of ORM objects from various
    :class:`.ReturnsRows` and other classes including:

    :class:`.Select`, :class:`.TextClause`, :class:`.TextualSelect`,
    :class:`.CompoundSelect`, :class`.Insert`, :class:`.Update`,
    and in theory, :class:`.Delete`.

    """

    __visit_name__ = "orm_from_statement"

    _compile_options = _ORMFromStatementCompileState.default_compile_options

    _compile_state_factory = _ORMFromStatementCompileState.create_for_statement

    _for_update_arg = None

    element: Union[ExecutableReturnsRows, TextClause]

    _adapt_on_names: bool

    _traverse_internals = [
        ("_raw_columns", InternalTraversal.dp_clauseelement_list),
        ("element", InternalTraversal.dp_clauseelement),
    ] + ExecutableStatement._executable_traverse_internals

    _cache_key_traversal = _traverse_internals + [
        ("_compile_options", InternalTraversal.dp_has_cache_key)
    ]

    is_from_statement = True

    def __init__(
        self,
        entities: Iterable[_ColumnsClauseArgument[Any]],
        element: Union[ExecutableReturnsRows, TextClause],
        _adapt_on_names: bool = True,
    ):
        self._raw_columns = [
            coercions.expect(
                roles.ColumnsClauseRole,
                ent,
                apply_propagate_attrs=self,
                post_inspect=True,
            )
            for ent in util.to_list(entities)
        ]
        self.element = element
        self.is_dml = element.is_dml
        self.is_select = element.is_select
        self.is_delete = element.is_delete
        self.is_insert = element.is_insert
        self.is_update = element.is_update
        self._label_style = (
            element._label_style if is_select_base(element) else None
        )
        self._adapt_on_names = _adapt_on_names