Class StatementLambdaElement

lib/sqlalchemy/sql/lambdas.py:500–650

Represent a composable SQL statement as a :class:`_sql.LambdaElement`. The :class:`_sql.StatementLambdaElement` is constructed using the :func:`_sql.lambda_stmt` function:: from sqlalchemy import lambda_stmt stmt = lambda_stmt(lambda: select(table)) Once constructed,

class StatementLambdaElement(
    roles.AllowsLambdaRole, LambdaElement, Executable
):
    """Represent a composable SQL statement as a :class:`_sql.LambdaElement`.

    The :class:`_sql.StatementLambdaElement` is constructed using the
    :func:`_sql.lambda_stmt` function::


        from sqlalchemy import lambda_stmt

        stmt = lambda_stmt(lambda: select(table))

    Once constructed, additional criteria can be built onto the statement
    by adding subsequent lambdas, which accept the existing statement
    object as a single parameter::

        stmt += lambda s: s.where(table.c.col == parameter)

    .. versionadded:: 1.4

    .. seealso::

        :ref:`engine_lambda_caching`

    """

    if TYPE_CHECKING:

        def __init__(
            self,
            fn: _StmtLambdaType,
            role: Type[SQLRole],
            opts: Union[Type[LambdaOptions], LambdaOptions] = LambdaOptions,
            apply_propagate_attrs: Optional[ClauseElement] = None,
        ): ...

    def __add__(
        self, other: _StmtLambdaElementType[Any]
    ) -> StatementLambdaElement:
        return self.add_criteria(other)

    def add_criteria(
        self,
        other: _StmtLambdaElementType[Any],
        enable_tracking: bool = True,
        track_on: Optional[Any] = None,
        track_closure_variables: bool = True,
        track_bound_values: bool = True,
    ) -> StatementLambdaElement:
        """Add new criteria to this :class:`_sql.StatementLambdaElement`.

        E.g.::

            >>> def my_stmt(parameter):
            ...     stmt = lambda_stmt(
            ...         lambda: select(table.c.x, table.c.y),
            ...     )