Represent the NULL keyword in a SQL statement. :class:`.Null` is accessed as a constant via the :func:`.null` function.
| 2621 | |
| 2622 | |
| 2623 | class Null(SingletonConstant, roles.ConstExprRole[None], ColumnElement[None]): |
| 2624 | """Represent the NULL keyword in a SQL statement. |
| 2625 | |
| 2626 | :class:`.Null` is accessed as a constant via the |
| 2627 | :func:`.null` function. |
| 2628 | |
| 2629 | """ |
| 2630 | |
| 2631 | __visit_name__ = "null" |
| 2632 | |
| 2633 | _traverse_internals: _TraverseInternalsType = [] |
| 2634 | _singleton: Null |
| 2635 | |
| 2636 | if not TYPE_CHECKING: |
| 2637 | |
| 2638 | @util.memoized_property |
| 2639 | def type(self) -> TypeEngine[_T]: # noqa: A001 |
| 2640 | return type_api.NULLTYPE |
| 2641 | |
| 2642 | @classmethod |
| 2643 | def _instance(cls) -> Null: |
| 2644 | """Return a constant :class:`.Null` construct.""" |
| 2645 | |
| 2646 | return Null._singleton |
| 2647 | |
| 2648 | |
| 2649 | Null._create_singleton() |
no outgoing calls
no test coverage detected