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# orm/decl_api.py # Copyright (C) 2005-2024 the SQLAlchemy authors and contributors # <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: https://www.opensource.org/licenses/mit-license.php """Public API functions and helpers for declarative.""" from __future__ import annotations import itertools import re import typing from typing import Any from typing import Callable from typing import cast from typing import ClassVar from typing import Dict from typing import FrozenSet from typing import Generic from typing import Iterable from typing import Iterator from typing import Mapping from typing import Optional from typing import overload from typing import Set from typing import Tuple from typing import Type from typing import TYPE_CHECKING from typing import TypeVar from typing import Union import weakref from . import attributes from . import clsregistry from . import instrumentation from . import interfaces from . import mapperlib from ._orm_constructors import composite from ._orm_constructors import deferred from ._orm_constructors import mapped_column from ._orm_constructors import relationship from ._orm_constructors import synonym from .attributes import InstrumentedAttribute from .base import _inspect_mapped_class from .base import _is_mapped_class from .base import Mapped from .base import ORMDescriptor from .decl_base import _add_attribute from .decl_base import _as_declarative from .decl_base import _ClassScanMapperConfig from .decl_base import _declarative_constructor from .decl_base import _DeferredMapperConfig from .decl_base import _del_attribute from .decl_base import _mapper from .descriptor_props import Composite from .descriptor_props import Synonym from .descriptor_props import Synonym as _orm_synonym from .mapper import Mapper from .properties import MappedColumn from .relationships import RelationshipProperty from .state import InstanceState from .. import exc from .. import inspection from .. import util from ..sql import sqltypes from ..sql.base import _NoArg from ..sql.elements import SQLCoreOperations from ..sql.schema import MetaData from ..sql.selectable import FromClause from ..util import hybridmethod from ..util import hybridproperty from ..util import typing as compat_typing from ..util.typing import CallableReference from ..util.typing import flatten_newtype from ..util.typing import is_generic from ..util.typing import is_literal from ..util.typing import is_newtype from ..util.typing import is_pep695 from ..util.typing import Literal from ..util.typing import Self if TYPE_CHECKING: from ._typing import _O from ._typing import _RegistryType from .decl_base import _DataclassArguments from .instrumentation import ClassManager from .interfaces import MapperProperty from .state import InstanceState # noqa from ..sql._typing import _TypeEngineArgument from ..sql.type_api import _MatchedOnType _T = TypeVar("_T", bound=Any) _TT = TypeVar("_TT", bound=Any) # it's not clear how to have Annotated, Union objects etc. as keys here # from a typing perspective so just leave it open ended for now _TypeAnnotationMapType = Mapping[Any, "_TypeEngineArgument[Any]"] _MutableTypeAnnotationMapType = Dict[Any, "_TypeEngineArgument[Any]"] _DeclaredAttrDecorated = Callable[ ..., Union[Mapped[_T], ORMDescriptor[_T], SQLCoreOperations[_T]] ] def has_inherited_table(cls: Type[_O]) -> bool: """Given a class, return True if any of the classes it inherits from has a mapped table, otherwise return False. This is used in declarative mixins to build attributes that behave differently for the base class vs. a subclass in an inheritance hierarchy. .. seealso:: :ref:`decl_mixin_inheritance` """ for class_ in cls.__mro__[1:]: if getattr(class_, "__table__", None) is not None: return True return False class _DynamicAttributesType(type): def __setattr__(cls, key: str, value: Any) -> None: if "__mapper__" in cls.__dict__: _add_attribute(cls, key, value) else: type.__setattr__(cls, key, value) def __delattr__(cls, key: str) -> None: if "__mapper__" in cls.__dict__: _del_attribute(cls, key) else: type.__delattr__(cls, key) class DeclarativeAttributeIntercept( _DynamicAttributesType, # Inspectable is used only by the mypy plugin inspection.Inspectable[Mapper[Any]], ): """Metaclass that may be used in conjunction with the :class:`_orm.DeclarativeBase` class to support addition of class attributes dynamically. """ @compat_typing.dataclass_transform( field_specifiers=( MappedColumn, RelationshipProperty, Composite, Synonym, mapped_column, relationship, composite, synonym, deferred, ), ) class DCTransformDeclarative(DeclarativeAttributeIntercept): """metaclass that includes @dataclass_transforms""" class DeclarativeMeta(DeclarativeAttributeIntercept): metadata: MetaData registry: RegistryType def __init__( cls, classname: Any, bases: Any, dict_: Any, **kw: Any ) -> None: # use cls.__dict__, which can be modified by an # __init_subclass__() method (#7900) dict_ = cls.__dict__ # early-consume registry from the initial declarative base, # assign privately to not conflict with subclass attributes named # "registry" reg = getattr(cls, "_sa_registry", None) if reg is None: reg = dict_.get("registry", None) if not isinstance(reg, registry): raise exc.InvalidRequestError( "Declarative base class has no 'registry' attribute, " "or registry is not a sqlalchemy.orm.registry() object" ) else: cls._sa_registry = reg if not cls.__dict__.get("__abstract__", False): _as_declarative(reg, cls, dict_) type.__init__(cls, classname, bases, dict_) def synonym_for( name: str, map_column: bool = False ) -> Callable[[Callable[..., Any]], Synonym[Any]]: """Decorator that produces an :func:`_orm.synonym` attribute in conjunction with a Python descriptor. The function being decorated is passed to :func:`_orm.synonym` as the :paramref:`.orm.synonym.descriptor` parameter:: class MyClass(Base): __tablename__ = 'my_table' id = Column(Integer, primary_key=True) _job_status = Column("job_status", String(50)) @synonym_for("job_status") @property def job_status(self): return "Status: %s" % self._job_status The :ref:`hybrid properties <mapper_hybrids>` feature of SQLAlchemy is typically preferred instead of synonyms, which is a more legacy feature. .. seealso:: :ref:`synonyms` - Overview of synonyms :func:`_orm.synonym` - the mapper-level function :ref:`mapper_hybrids` - The Hybrid Attribute extension provides an updated approach to augmenting attribute behavior more flexibly than can be achieved with synonyms. """ def decorate(fn: Callable[..., Any]) -> Synonym[Any]: return _orm_synonym(name, map_column=map_column, descriptor=fn) return decorate class _declared_attr_common: def __init__( self, fn: Callable[..., Any], cascading: bool = False, quiet: bool = False, ): # suppport # @declared_attr # @classmethod # def foo(cls) -> Mapped[thing]: # ... # which seems to help typing tools interpret the fn as a classmethod # for situations where needed if isinstance(fn, classmethod): fn = fn.__func__ self.fget = fn self._cascading = cascading self._quiet = quiet self.__doc__ = fn.__doc__ def _collect_return_annotation(self) -> Optional[Type[Any]]: return util.get_annotations(self.fget).get("return") def __get__(self, instance: Optional[object], owner: Any) -> Any: # the declared_attr needs to make use of a cache that exists # for the span of the declarative scan_attributes() phase. # to achieve this we look at the class manager that's configured. # note this method should not be called outside of the declarative # setup phase cls = owner manager = attributes.opt_manager_of_class(cls) if manager is None: if not re.match(r"^__.+__$", self.fget.__name__): # if there is no manager at all, then this class hasn't been # run through declarative or mapper() at all, emit a warning. util.warn( "Unmanaged access of declarative attribute %s from " "non-mapped class %s" % (self.fget.__name__, cls.__name__) ) return self.fget(cls) elif manager.is_mapped: # the class is mapped, which means we're outside of the declarative # scan setup, just run the function. return self.fget(cls) # here, we are inside of the declarative scan. use the registry # that is tracking the values of these attributes. declarative_scan = manager.declarative_scan() # assert that we are in fact in the declarative scan assert declarative_scan is not None reg = declarative_scan.declared_attr_reg if self in reg: return reg[self] else: reg[self] = obj = self.fget(cls) return obj class _declared_directive(_declared_attr_common, Generic[_T]): # see mapping_api.rst for docstring if typing.TYPE_CHECKING: def __init__( self, fn: Callable[..., _T], cascading: bool = False, ): ... def __get__(self, instance: Optional[object], owner: Any) -> _T: ... def __set__(self, instance: Any, value: Any) -> None: ... def __delete__(self, instance: Any) -> None: ... def __call__(self, fn: Callable[..., _TT]) -> _declared_directive[_TT]: # extensive fooling of mypy underway... ... class declared_attr(interfaces._MappedAttribute[_T], _declared_attr_common): """Mark a class-level method as representing the definition of a mapped property or Declarative directive. :class:`_orm.declared_attr` is typically applied as a decorator to a class level method, turning the attribute into a scalar-like property that can be invoked from the uninstantiated class. The Declarative mapping process looks for these :class:`_orm.declared_attr` callables as it scans classes, and assumes any attribute marked with :class:`_orm.declared_attr` will be a callable that will produce an object specific to the Declarative mapping or table configuration. :class:`_orm.declared_attr` is usually applicable to :ref:`mixins <orm_mixins_toplevel>`, to define relationships that are to be applied to different implementors of the class. It may also be used to define dynamically generated column expressions and other Declarative attributes. Example:: class ProvidesUserMixin: "A mixin that adds a 'user' relationship to classes." user_id: Mapped[int] = mapped_column(ForeignKey("user_table.id")) @declared_attr def user(cls) -> Mapped["User"]: return relationship("User") When used with Declarative directives such as ``__tablename__``, the :meth:`_orm.declared_attr.directive` modifier may be used which indicates to :pep:`484` typing tools that the given method is not dealing with :class:`_orm.Mapped` attributes:: class CreateTableName: @declared_attr.directive def __tablename__(cls) -> str: return cls.__name__.lower() :class:`_orm.declared_attr` can also be applied directly to mapped classes, to allow for attributes that dynamically configure themselves on subclasses when using mapped inheritance schemes. Below illustrates :class:`_orm.declared_attr` to create a dynamic scheme for generating the :paramref:`_orm.Mapper.polymorphic_identity` parameter for subclasses:: class Employee(Base): __tablename__ = 'employee' id: Mapped[int] = mapped_column(primary_key=True) type: Mapped[str] = mapped_column(String(50)) @declared_attr.directive def __mapper_args__(cls) -> Dict[str, Any]: if cls.__name__ == 'Employee': return { "polymorphic_on":cls.type, "polymorphic_identity":"Employee" } else: return {"polymorphic_identity":cls.__name__} class Engineer(Employee): pass :class:`_orm.declared_attr` supports decorating functions that are explicitly decorated with ``@classmethod``. This is never necessary from a runtime perspective, however may be needed in order to support :pep:`484` typing tools that don't otherwise recognize the decorated function as having class-level behaviors for the ``cls`` parameter:: class SomethingMixin: x: Mapped[int] y: Mapped[int] @declared_attr @classmethod def x_plus_y(cls) -> Mapped[int]: return column_property(cls.x + cls.y) .. versionadded:: 2.0 - :class:`_orm.declared_attr` can accommodate a function decorated with ``@classmethod`` to help with :pep:`484` integration where needed. .. seealso:: :ref:`orm_mixins_toplevel` - Declarative Mixin documentation with background on use patterns for :class:`_orm.declared_attr`. """ # noqa: E501 if typing.TYPE_CHECKING: def __init__( self, fn: _DeclaredAttrDecorated[_T], cascading: bool = False, ): ... def __set__(self, instance: Any, value: Any) -> None: ... def __delete__(self, instance: Any) -> None: ... # this is the Mapped[] API where at class descriptor get time we want # the type checker to see InstrumentedAttribute[_T]. However the # callable function prior to mapping in fact calls the given # declarative function that does not return InstrumentedAttribute @overload def __get__( self, instance: None, owner: Any ) -> InstrumentedAttribute[_T]: ... @overload def __get__(self, instance: object, owner: Any) -> _T: ... def __get__( self, instance: Optional[object], owner: Any ) -> Union[InstrumentedAttribute[_T], _T]: ... @hybridmethod def _stateful(cls, **kw: Any) -> _stateful_declared_attr[_T]: return _stateful_declared_attr(**kw) @hybridproperty def directive(cls) -> _declared_directive[Any]: # see mapping_api.rst for docstring return _declared_directive # type: ignore @hybridproperty def cascading(cls) -> _stateful_declared_attr[_T]: # see mapping_api.rst for docstring return cls._stateful(cascading=True) class _stateful_declared_attr(declared_attr[_T]): kw: Dict[str, Any] def __init__(self, **kw: Any): self.kw = kw @hybridmethod def _stateful(self, **kw: Any) -> _stateful_declared_attr[_T]: new_kw = self.kw.copy() new_kw.update(kw) return _stateful_declared_attr(**new_kw) def __call__(self, fn: _DeclaredAttrDecorated[_T]) -> declared_attr[_T]: return declared_attr(fn, **self.kw) def declarative_mixin(cls: Type[_T]) -> Type[_T]: """Mark a class as providing the feature of "declarative mixin". E.g.:: from sqlalchemy.orm import declared_attr from sqlalchemy.orm import declarative_mixin @declarative_mixin class MyMixin: @declared_attr def __tablename__(cls): return cls.__name__.lower() __table_args__ = {'mysql_engine': 'InnoDB'} __mapper_args__= {'always_refresh': True} id = Column(Integer, primary_key=True) class MyModel(MyMixin, Base): name = Column(String(1000)) The :func:`_orm.declarative_mixin` decorator currently does not modify the given class in any way; it's current purpose is strictly to assist the :ref:`Mypy plugin <mypy_toplevel>` in being able to identify SQLAlchemy declarative mixin classes when no other context is present. .. versionadded:: 1.4.6 .. seealso:: :ref:`orm_mixins_toplevel` :ref:`mypy_declarative_mixins` - in the :ref:`Mypy plugin documentation <mypy_toplevel>` """ # noqa: E501 return cls def _setup_declarative_base(cls: Type[Any]) -> None: if "metadata" in cls.__dict__: metadata = cls.__dict__["metadata"] else: metadata = None if "type_annotation_map" in cls.__dict__: type_annotation_map = cls.__dict__["type_annotation_map"] else: type_annotation_map = None reg = cls.__dict__.get("registry", None) if reg is not None: if not isinstance(reg, registry): raise exc.InvalidRequestError( "Declarative base class has a 'registry' attribute that is " "not an instance of sqlalchemy.orm.registry()" ) elif type_annotation_map is not None: raise exc.InvalidRequestError( "Declarative base class has both a 'registry' attribute and a " "type_annotation_map entry. Per-base type_annotation_maps " "are not supported. Please apply the type_annotation_map " "to this registry directly." ) else: reg = registry( metadata=metadata, type_annotation_map=type_annotation_map ) cls.registry = reg cls._sa_registry = reg if "metadata" not in cls.__dict__: cls.metadata = cls.registry.metadata if getattr(cls, "__init__", object.__init__) is object.__init__: cls.__init__ = cls.registry.constructor class MappedAsDataclass(metaclass=DCTransformDeclarative): """Mixin class to indicate when mapping this class, also convert it to be a dataclass. .. seealso:: :ref:`orm_declarative_native_dataclasses` - complete background on SQLAlchemy native dataclass mapping .. versionadded:: 2.0 """ def __init_subclass__( cls, init: Union[_NoArg, bool] = _NoArg.NO_ARG, repr: Union[_NoArg, bool] = _NoArg.NO_ARG, # noqa: A002 eq: Union[_NoArg, bool] = _NoArg.NO_ARG, order: Union[_NoArg, bool] = _NoArg.NO_ARG, unsafe_hash: Union[_NoArg, bool] = _NoArg.NO_ARG, match_args: Union[_NoArg, bool] = _NoArg.NO_ARG, kw_only: Union[_NoArg, bool] = _NoArg.NO_ARG, dataclass_callable: Union[ _NoArg, Callable[..., Type[Any]] ] = _NoArg.NO_ARG, **kw: Any, ) -> None: apply_dc_transforms: _DataclassArguments = { "init": init, "repr": repr, "eq": eq, "order": order, "unsafe_hash": unsafe_hash, "match_args": match_args, "kw_only": kw_only, "dataclass_callable": dataclass_callable, } current_transforms: _DataclassArguments if hasattr(cls, "_sa_apply_dc_transforms"): current = cls._sa_apply_dc_transforms _ClassScanMapperConfig._assert_dc_arguments(current) cls._sa_apply_dc_transforms = current_transforms = { # type: ignore # noqa: E501 k: current.get(k, _NoArg.NO_ARG) if v is _NoArg.NO_ARG else v for k, v in apply_dc_transforms.items() } else: cls._sa_apply_dc_transforms = current_transforms = ( apply_dc_transforms ) super().__init_subclass__(**kw) if not _is_mapped_class(cls): new_anno = ( _ClassScanMapperConfig._update_annotations_for_non_mapped_class )(cls) _ClassScanMapperConfig._apply_dataclasses_to_any_class( current_transforms, cls, new_anno ) class DeclarativeBase( # Inspectable is used only by the mypy plugin inspection.Inspectable[InstanceState[Any]], metaclass=DeclarativeAttributeIntercept, ): """Base class used for declarative class definitions. The :class:`_orm.DeclarativeBase` allows for the creation of new declarative bases in such a way that is compatible with type checkers:: from sqlalchemy.orm import DeclarativeBase class Base(DeclarativeBase): pass The above ``Base`` class is now usable as the base for new declarative mappings. The superclass makes use of the ``__init_subclass__()`` method to set up new classes and metaclasses aren't used. When first used, the :class:`_orm.DeclarativeBase` class instantiates a new :class:`_orm.registry` to be used with the base, assuming one was not provided explicitly. The :class:`_orm.DeclarativeBase` class supports class-level attributes which act as parameters for the construction of this registry; such as to indicate a specific :class:`_schema.MetaData` collection as well as a specific value for :paramref:`_orm.registry.type_annotation_map`:: from typing_extensions import Annotated from sqlalchemy import BigInteger from sqlalchemy import MetaData from sqlalchemy import String from sqlalchemy.orm import DeclarativeBase bigint = Annotated[int, "bigint"] my_metadata = MetaData() class Base(DeclarativeBase): metadata = my_metadata type_annotation_map = { str: String().with_variant(String(255), "mysql", "mariadb"), bigint: BigInteger() } Class-level attributes which may be specified include: :param metadata: optional :class:`_schema.MetaData` collection. If a :class:`_orm.registry` is constructed automatically, this :class:`_schema.MetaData` collection will be used to construct it. Otherwise, the local :class:`_schema.MetaData` collection will supercede that used by an existing :class:`_orm.registry` passed using the :paramref:`_orm.DeclarativeBase.registry` parameter. :param type_annotation_map: optional type annotation map that will be passed to the :class:`_orm.registry` as :paramref:`_orm.registry.type_annotation_map`. :param registry: supply a pre-existing :class:`_orm.registry` directly. .. versionadded:: 2.0 Added :class:`.DeclarativeBase`, so that declarative base classes may be constructed in such a way that is also recognized by :pep:`484` type checkers. As a result, :class:`.DeclarativeBase` and other subclassing-oriented APIs should be seen as superseding previous "class returned by a function" APIs, namely :func:`_orm.declarative_base` and :meth:`_orm.registry.generate_base`, where the base class returned cannot be recognized by type checkers without using plugins. **__init__ behavior** In a plain Python class, the base-most ``__init__()`` method in the class hierarchy is ``object.__init__()``, which accepts no arguments. However, when the :class:`_orm.DeclarativeBase` subclass is first declared, the class is given an ``__init__()`` method that links to the :paramref:`_orm.registry.constructor` constructor function, if no ``__init__()`` method is already present; this is the usual declarative constructor that will assign keyword arguments as attributes on the instance, assuming those attributes are established at the class level (i.e. are mapped, or are linked to a descriptor). This constructor is **never accessed by a mapped class without being called explicitly via super()**, as mapped classes are themselves given an ``__init__()`` method directly which calls :paramref:`_orm.registry.constructor`, so in the default case works independently of what the base-most ``__init__()`` method does. .. versionchanged:: 2.0.1 :class:`_orm.DeclarativeBase` has a default constructor that links to :paramref:`_orm.registry.constructor` by default, so that calls to ``super().__init__()`` can access this constructor. Previously, due to an implementation mistake, this default constructor was missing, and calling ``super().__init__()`` would invoke ``object.__init__()``. The :class:`_orm.DeclarativeBase` subclass may also declare an explicit ``__init__()`` method which will replace the use of the :paramref:`_orm.registry.constructor` function at this level:: class Base(DeclarativeBase): def __init__(self, id=None): self.id = id Mapped classes still will not invoke this constructor implicitly; it remains only accessible by calling ``super().__init__()``:: class MyClass(Base): def __init__(self, id=None, name=None): self.name = name super().__init__(id=id) Note that this is a different behavior from what functions like the legacy :func:`_orm.declarative_base` would do; the base created by those functions would always install :paramref:`_orm.registry.constructor` for ``__init__()``. """ if typing.TYPE_CHECKING: def _sa_inspect_type(self) -> Mapper[Self]: ... def _sa_inspect_instance(self) -> InstanceState[Self]: ... _sa_registry: ClassVar[_RegistryType] registry: ClassVar[_RegistryType] """Refers to the :class:`_orm.registry` in use where new :class:`_orm.Mapper` objects will be associated.""" metadata: ClassVar[MetaData] """Refers to the :class:`_schema.MetaData` collection that will be used for new :class:`_schema.Table` objects. .. seealso:: :ref:`orm_declarative_metadata` """ __name__: ClassVar[str] # this ideally should be Mapper[Self], but mypy as of 1.4.1 does not # like it, and breaks the declared_attr_one test. Pyright/pylance is # ok with it. __mapper__: ClassVar[Mapper[Any]] """The :class:`_orm.Mapper` object to which a particular class is mapped. May also be acquired using :func:`_sa.inspect`, e.g. ``inspect(klass)``. """ __table__: ClassVar[FromClause] """The :class:`_sql.FromClause` to which a particular subclass is mapped. This is usually an instance of :class:`_schema.Table` but may also refer to other kinds of :class:`_sql.FromClause` such as :class:`_sql.Subquery`, depending on how the class is mapped. .. seealso:: :ref:`orm_declarative_metadata` """ # pyright/pylance do not consider a classmethod a ClassVar so use Any # https://github.com/microsoft/pylance-release/issues/3484 __tablename__: Any """String name to assign to the generated :class:`_schema.Table` object, if not specified directly via :attr:`_orm.DeclarativeBase.__table__`. .. seealso:: :ref:`orm_declarative_table` """ __mapper_args__: Any """Dictionary of arguments which will be passed to the :class:`_orm.Mapper` constructor. .. seealso:: :ref:`orm_declarative_mapper_options` """ __table_args__: Any """A dictionary or tuple of arguments that will be passed to the :class:`_schema.Table` constructor. See :ref:`orm_declarative_table_configuration` for background on the specific structure of this collection. .. seealso:: :ref:`orm_declarative_table_configuration` """ def __init__(self, **kw: Any): ... def __init_subclass__(cls, **kw: Any) -> None: if DeclarativeBase in cls.__bases__: _check_not_declarative(cls, DeclarativeBase) _setup_declarative_base(cls) else: _as_declarative(cls._sa_registry, cls, cls.__dict__) super().__init_subclass__(**kw) def _check_not_declarative(cls: Type[Any], base: Type[Any]) -> None: cls_dict = cls.__dict__ if ( "__table__" in cls_dict and not ( callable(cls_dict["__table__"]) or hasattr(cls_dict["__table__"], "__get__") ) ) or isinstance(cls_dict.get("__tablename__", None), str): raise exc.InvalidRequestError( f"Cannot use {base.__name__!r} directly as a declarative base " "class. Create a Base by creating a subclass of it." ) class DeclarativeBaseNoMeta( # Inspectable is used only by the mypy plugin inspection.Inspectable[InstanceState[Any]] ): """Same as :class:`_orm.DeclarativeBase`, but does not use a metaclass to intercept new attributes. The :class:`_orm.DeclarativeBaseNoMeta` base may be used when use of custom metaclasses is desirable. .. versionadded:: 2.0 """ _sa_registry: ClassVar[_RegistryType] registry: ClassVar[_RegistryType] """Refers to the :class:`_orm.registry` in use where new :class:`_orm.Mapper` objects will be associated.""" metadata: ClassVar[MetaData] """Refers to the :class:`_schema.MetaData` collection that will be used for new :class:`_schema.Table` objects. .. seealso:: :ref:`orm_declarative_metadata` """ # this ideally should be Mapper[Self], but mypy as of 1.4.1 does not # like it, and breaks the declared_attr_one test. Pyright/pylance is # ok with it. __mapper__: ClassVar[Mapper[Any]] """The :class:`_orm.Mapper` object to which a particular class is mapped. May also be acquired using :func:`_sa.inspect`, e.g. ``inspect(klass)``. """ __table__: Optional[FromClause] """The :class:`_sql.FromClause` to which a particular subclass is mapped. This is usually an instance of :class:`_schema.Table` but may also refer to other kinds of :class:`_sql.FromClause` such as :class:`_sql.Subquery`, depending on how the class is mapped. .. seealso:: :ref:`orm_declarative_metadata` """ if typing.TYPE_CHECKING: def _sa_inspect_type(self) -> Mapper[Self]: ... def _sa_inspect_instance(self) -> InstanceState[Self]: ... __tablename__: Any """String name to assign to the generated :class:`_schema.Table` object, if not specified directly via :attr:`_orm.DeclarativeBase.__table__`. .. seealso:: :ref:`orm_declarative_table` """ __mapper_args__: Any """Dictionary of arguments which will be passed to the :class:`_orm.Mapper` constructor. .. seealso:: :ref:`orm_declarative_mapper_options` """ __table_args__: Any """A dictionary or tuple of arguments that will be passed to the :class:`_schema.Table` constructor. See :ref:`orm_declarative_table_configuration` for background on the specific structure of this collection. .. seealso:: :ref:`orm_declarative_table_configuration` """ def __init__(self, **kw: Any): ... def __init_subclass__(cls, **kw: Any) -> None: if DeclarativeBaseNoMeta in cls.__bases__: _check_not_declarative(cls, DeclarativeBaseNoMeta) _setup_declarative_base(cls) else: _as_declarative(cls._sa_registry, cls, cls.__dict__) super().__init_subclass__(**kw) def add_mapped_attribute( target: Type[_O], key: str, attr: MapperProperty[Any] ) -> None: """Add a new mapped attribute to an ORM mapped class. E.g.:: add_mapped_attribute(User, "addresses", relationship(Address)) This may be used for ORM mappings that aren't using a declarative metaclass that intercepts attribute set operations. .. versionadded:: 2.0 """ _add_attribute(target, key, attr) def declarative_base( *, metadata: Optional[MetaData] = None, mapper: Optional[Callable[..., Mapper[Any]]] = None, cls: Type[Any] = object, name: str = "Base", class_registry: Optional[clsregistry._ClsRegistryType] = None, type_annotation_map: Optional[_TypeAnnotationMapType] = None, constructor: Callable[..., None] = _declarative_constructor, metaclass: Type[Any] = DeclarativeMeta, ) -> Any: r"""Construct a base class for declarative class definitions. The new base class will be given a metaclass that produces appropriate :class:`~sqlalchemy.schema.Table` objects and makes the appropriate :class:`_orm.Mapper` calls based on the information provided declaratively in the class and any subclasses of the class. .. versionchanged:: 2.0 Note that the :func:`_orm.declarative_base` function is superseded by the new :class:`_orm.DeclarativeBase` class, which generates a new "base" class using subclassing, rather than return value of a function. This allows an approach that is compatible with :pep:`484` typing tools. The :func:`_orm.declarative_base` function is a shorthand version of using the :meth:`_orm.registry.generate_base` method. That is, the following:: from sqlalchemy.orm import declarative_base Base = declarative_base() Is equivalent to:: from sqlalchemy.orm import registry mapper_registry = registry() Base = mapper_registry.generate_base() See the docstring for :class:`_orm.registry` and :meth:`_orm.registry.generate_base` for more details. .. versionchanged:: 1.4 The :func:`_orm.declarative_base` function is now a specialization of the more generic :class:`_orm.registry` class. The function also moves to the ``sqlalchemy.orm`` package from the ``declarative.ext`` package. :param metadata: An optional :class:`~sqlalchemy.schema.MetaData` instance. All :class:`~sqlalchemy.schema.Table` objects implicitly declared by subclasses of the base will share this MetaData. A MetaData instance will be created if none is provided. The :class:`~sqlalchemy.schema.MetaData` instance will be available via the ``metadata`` attribute of the generated declarative base class. :param mapper: An optional callable, defaults to :class:`_orm.Mapper`. Will be used to map subclasses to their Tables. :param cls: Defaults to :class:`object`. A type to use as the base for the generated declarative base class. May be a class or tuple of classes. :param name: Defaults to ``Base``. The display name for the generated class. Customizing this is not required, but can improve clarity in tracebacks and debugging. :param constructor: Specify the implementation for the ``__init__`` function on a mapped class that has no ``__init__`` of its own. Defaults to an implementation that assigns \**kwargs for declared fields and relationships to an instance. If ``None`` is supplied, no __init__ will be provided and construction will fall back to cls.__init__ by way of the normal Python semantics. :param class_registry: optional dictionary that will serve as the registry of class names-> mapped classes when string names are used to identify classes inside of :func:`_orm.relationship` and others. Allows two or more declarative base classes to share the same registry of class names for simplified inter-base relationships. :param type_annotation_map: optional dictionary of Python types to SQLAlchemy :class:`_types.TypeEngine` classes or instances. This is used exclusively by the :class:`_orm.MappedColumn` construct to produce column types based on annotations within the :class:`_orm.Mapped` type. .. versionadded:: 2.0 .. seealso:: :ref:`orm_declarative_mapped_column_type_map` :param metaclass: Defaults to :class:`.DeclarativeMeta`. A metaclass or __metaclass__ compatible callable to use as the meta type of the generated declarative base class. .. seealso:: :class:`_orm.registry` """ return registry( metadata=metadata, class_registry=class_registry, constructor=constructor, type_annotation_map=type_annotation_map, ).generate_base( mapper=mapper, cls=cls, name=name, metaclass=metaclass, ) class registry: """Generalized registry for mapping classes. The :class:`_orm.registry` serves as the basis for maintaining a collection of mappings, and provides configurational hooks used to map classes. The three general kinds of mappings supported are Declarative Base, Declarative Decorator, and Imperative Mapping. All of these mapping styles may be used interchangeably: * :meth:`_orm.registry.generate_base` returns a new declarative base class, and is the underlying implementation of the :func:`_orm.declarative_base` function. * :meth:`_orm.registry.mapped` provides a class decorator that will apply declarative mapping to a class without the use of a declarative base class. * :meth:`_orm.registry.map_imperatively` will produce a :class:`_orm.Mapper` for a class without scanning the class for declarative class attributes. This method suits the use case historically provided by the ``sqlalchemy.orm.mapper()`` classical mapping function, which is removed as of SQLAlchemy 2.0. .. versionadded:: 1.4 .. seealso:: :ref:`orm_mapping_classes_toplevel` - overview of class mapping styles. """ _class_registry: clsregistry._ClsRegistryType _managers: weakref.WeakKeyDictionary[ClassManager[Any], Literal[True]] _non_primary_mappers: weakref.WeakKeyDictionary[Mapper[Any], Literal[True]] metadata: MetaData constructor: CallableReference[Callable[..., None]] type_annotation_map: _MutableTypeAnnotationMapType _dependents: Set[_RegistryType] _dependencies: Set[_RegistryType] _new_mappers: bool def __init__( self, *, metadata: Optional[MetaData] = None, class_registry: Optional[clsregistry._ClsRegistryType] = None, type_annotation_map: Optional[_TypeAnnotationMapType] = None, constructor: Callable[..., None] = _declarative_constructor, ): r"""Construct a new :class:`_orm.registry` :param metadata: An optional :class:`_schema.MetaData` instance. All :class:`_schema.Table` objects generated using declarative table mapping will make use of this :class:`_schema.MetaData` collection. If this argument is left at its default of ``None``, a blank :class:`_schema.MetaData` collection is created. :param constructor: Specify the implementation for the ``__init__`` function on a mapped class that has no ``__init__`` of its own. Defaults to an implementation that assigns \**kwargs for declared fields and relationships to an instance. If ``None`` is supplied, no __init__ will be provided and construction will fall back to cls.__init__ by way of the normal Python semantics. :param class_registry: optional dictionary that will serve as the registry of class names-> mapped classes when string names are used to identify classes inside of :func:`_orm.relationship` and others. Allows two or more declarative base classes to share the same registry of class names for simplified inter-base relationships. :param type_annotation_map: optional dictionary of Python types to SQLAlchemy :class:`_types.TypeEngine` classes or instances. The provided dict will update the default type mapping. This is used exclusively by the :class:`_orm.MappedColumn` construct to produce column types based on annotations within the :class:`_orm.Mapped` type. .. versionadded:: 2.0 .. seealso:: :ref:`orm_declarative_mapped_column_type_map` """ lcl_metadata = metadata or MetaData() if class_registry is None: class_registry = weakref.WeakValueDictionary() self._class_registry = class_registry self._managers = weakref.WeakKeyDictionary() self._non_primary_mappers = weakref.WeakKeyDictionary() self.metadata = lcl_metadata self.constructor = constructor self.type_annotation_map = {} if type_annotation_map is not None: self.update_type_annotation_map(type_annotation_map) self._dependents = set() self._dependencies = set() self._new_mappers = False with mapperlib._CONFIGURE_MUTEX: mapperlib._mapper_registries[self] = True def update_type_annotation_map( self, type_annotation_map: _TypeAnnotationMapType, ) -> None: """update the :paramref:`_orm.registry.type_annotation_map` with new values.""" self.type_annotation_map.update( { sub_type: sqltype for typ, sqltype in type_annotation_map.items() for sub_type in compat_typing.expand_unions( typ, include_union=True, discard_none=True ) } ) def _resolve_type( self, python_type: _MatchedOnType ) -> Optional[sqltypes.TypeEngine[Any]]: python_type_to_check = python_type while is_pep695(python_type_to_check): python_type_to_check = python_type_to_check.__value__ check_is_pt = python_type is python_type_to_check python_type_type: Type[Any] search: Iterable[Tuple[_MatchedOnType, Type[Any]]] if is_generic(python_type_to_check): if is_literal(python_type_to_check): python_type_type = cast("Type[Any]", python_type_to_check) search = ( # type: ignore[assignment] (python_type, python_type_type), (Literal, python_type_type), ) else: python_type_type = python_type_to_check.__origin__ search = ((python_type, python_type_type),) elif is_newtype(python_type_to_check): python_type_type = flatten_newtype(python_type_to_check) search = ((python_type, python_type_type),) elif isinstance(python_type_to_check, type): python_type_type = python_type_to_check search = ( (pt if check_is_pt else python_type, pt) for pt in python_type_type.__mro__ ) else: python_type_type = python_type_to_check # type: ignore[assignment] search = ((python_type, python_type_type),) for pt, flattened in search: # we search through full __mro__ for types. however... sql_type = self.type_annotation_map.get(pt) if sql_type is None: sql_type = sqltypes._type_map_get(pt) # type: ignore # noqa: E501 if sql_type is not None: sql_type_inst = sqltypes.to_instance(sql_type) # ... this additional step will reject most # type -> supertype matches, such as if we had # a MyInt(int) subclass. note also we pass NewType() # here directly; these always have to be in the # type_annotation_map to be useful resolved_sql_type = sql_type_inst._resolve_for_python_type( python_type_type, pt, flattened, ) if resolved_sql_type is not None: return resolved_sql_type return None @property def mappers(self) -> FrozenSet[Mapper[Any]]: """read only collection of all :class:`_orm.Mapper` objects.""" return frozenset(manager.mapper for manager in self._managers).union( self._non_primary_mappers ) def _set_depends_on(self, registry: RegistryType) -> None: if registry is self: return registry._dependents.add(self) self._dependencies.add(registry) def _flag_new_mapper(self, mapper: Mapper[Any]) -> None: mapper._ready_for_configure = True if self._new_mappers: return for reg in self._recurse_with_dependents({self}): reg._new_mappers = True @classmethod def _recurse_with_dependents( cls, registries: Set[RegistryType] ) -> Iterator[RegistryType]: todo = registries done = set() while todo: reg = todo.pop() done.add(reg) # if yielding would remove dependents, make sure we have # them before todo.update(reg._dependents.difference(done)) yield reg # if yielding would add dependents, make sure we have them # after todo.update(reg._dependents.difference(done)) @classmethod def _recurse_with_dependencies( cls, registries: Set[RegistryType] ) -> Iterator[RegistryType]: todo = registries done = set() while todo: reg = todo.pop() done.add(reg) # if yielding would remove dependencies, make sure we have # them before todo.update(reg._dependencies.difference(done)) yield reg # if yielding would remove dependencies, make sure we have # them before todo.update(reg._dependencies.difference(done)) def _mappers_to_configure(self) -> Iterator[Mapper[Any]]: return itertools.chain( ( manager.mapper for manager in list(self._managers) if manager.is_mapped and not manager.mapper.configured and manager.mapper._ready_for_configure ), ( npm for npm in list(self._non_primary_mappers) if not npm.configured and npm._ready_for_configure ), ) def _add_non_primary_mapper(self, np_mapper: Mapper[Any]) -> None: self._non_primary_mappers[np_mapper] = True def _dispose_cls(self, cls: Type[_O]) -> None: clsregistry.remove_class(cls.__name__, cls, self._class_registry) def _add_manager(self, manager: ClassManager[Any]) -> None: self._managers[manager] = True if manager.is_mapped: raise exc.ArgumentError( "Class '%s' already has a primary mapper defined. " % manager.class_ ) assert manager.registry is None manager.registry = self def configure(self, cascade: bool = False) -> None: """Configure all as-yet unconfigured mappers in this :class:`_orm.registry`. The configure step is used to reconcile and initialize the :func:`_orm.relationship` linkages between mapped classes, as well as to invoke configuration events such as the :meth:`_orm.MapperEvents.before_configured` and :meth:`_orm.MapperEvents.after_configured`, which may be used by ORM extensions or user-defined extension hooks. If one or more mappers in this registry contain :func:`_orm.relationship` constructs that refer to mapped classes in other registries, this registry is said to be *dependent* on those registries. In order to configure those dependent registries automatically, the :paramref:`_orm.registry.configure.cascade` flag should be set to ``True``. Otherwise, if they are not configured, an exception will be raised. The rationale behind this behavior is to allow an application to programmatically invoke configuration of registries while controlling whether or not the process implicitly reaches other registries. As an alternative to invoking :meth:`_orm.registry.configure`, the ORM function :func:`_orm.configure_mappers` function may be used to ensure configuration is complete for all :class:`_orm.registry` objects in memory. This is generally simpler to use and also predates the usage of :class:`_orm.registry` objects overall. However, this function will impact all mappings throughout the running Python process and may be more memory/time consuming for an application that has many registries in use for different purposes that may not be needed immediately. .. seealso:: :func:`_orm.configure_mappers` .. versionadded:: 1.4.0b2 """ mapperlib._configure_registries({self}, cascade=cascade) def dispose(self, cascade: bool = False) -> None: """Dispose of all mappers in this :class:`_orm.registry`. After invocation, all the classes that were mapped within this registry will no longer have class instrumentation associated with them. This method is the per-:class:`_orm.registry` analogue to the application-wide :func:`_orm.clear_mappers` function. If this registry contains mappers that are dependencies of other registries, typically via :func:`_orm.relationship` links, then those registries must be disposed as well. When such registries exist in relation to this one, their :meth:`_orm.registry.dispose` method will also be called, if the :paramref:`_orm.registry.dispose.cascade` flag is set to ``True``; otherwise, an error is raised if those registries were not already disposed. .. versionadded:: 1.4.0b2 .. seealso:: :func:`_orm.clear_mappers` """ mapperlib._dispose_registries({self}, cascade=cascade) def _dispose_manager_and_mapper(self, manager: ClassManager[Any]) -> None: if "mapper" in manager.__dict__: mapper = manager.mapper mapper._set_dispose_flags() class_ = manager.class_ self._dispose_cls(class_) instrumentation._instrumentation_factory.unregister(class_) def generate_base( self, mapper: Optional[Callable[..., Mapper[Any]]] = None, cls: Type[Any] = object, name: str = "Base", metaclass: Type[Any] = DeclarativeMeta, ) -> Any: """Generate a declarative base class. Classes that inherit from the returned class object will be automatically mapped using declarative mapping. E.g.:: from sqlalchemy.orm import registry mapper_registry = registry() Base = mapper_registry.generate_base() class MyClass(Base): __tablename__ = "my_table" id = Column(Integer, primary_key=True) The above dynamically generated class is equivalent to the non-dynamic example below:: from sqlalchemy.orm import registry from sqlalchemy.orm.decl_api import DeclarativeMeta mapper_registry = registry() class Base(metaclass=DeclarativeMeta): __abstract__ = True registry = mapper_registry metadata = mapper_registry.metadata __init__ = mapper_registry.constructor .. versionchanged:: 2.0 Note that the :meth:`_orm.registry.generate_base` method is superseded by the new :class:`_orm.DeclarativeBase` class, which generates a new "base" class using subclassing, rather than return value of a function. This allows an approach that is compatible with :pep:`484` typing tools. The :meth:`_orm.registry.generate_base` method provides the implementation for the :func:`_orm.declarative_base` function, which creates the :class:`_orm.registry` and base class all at once. See the section :ref:`orm_declarative_mapping` for background and examples. :param mapper: An optional callable, defaults to :class:`_orm.Mapper`. This function is used to generate new :class:`_orm.Mapper` objects. :param cls: Defaults to :class:`object`. A type to use as the base for the generated declarative base class. May be a class or tuple of classes. :param name: Defaults to ``Base``. The display name for the generated class. Customizing this is not required, but can improve clarity in tracebacks and debugging. :param metaclass: Defaults to :class:`.DeclarativeMeta`. A metaclass or __metaclass__ compatible callable to use as the meta type of the generated declarative base class. .. seealso:: :ref:`orm_declarative_mapping` :func:`_orm.declarative_base` """ metadata = self.metadata bases = not isinstance(cls, tuple) and (cls,) or cls class_dict: Dict[str, Any] = dict(registry=self, metadata=metadata) if isinstance(cls, type): class_dict["__doc__"] = cls.__doc__ if self.constructor is not None: class_dict["__init__"] = self.constructor class_dict["__abstract__"] = True if mapper: class_dict["__mapper_cls__"] = mapper if hasattr(cls, "__class_getitem__"): def __class_getitem__(cls: Type[_T], key: Any) -> Type[_T]: # allow generic classes in py3.9+ return cls class_dict["__class_getitem__"] = __class_getitem__ return metaclass(name, bases, class_dict) @compat_typing.dataclass_transform( field_specifiers=( MappedColumn, RelationshipProperty, Composite, Synonym, mapped_column, relationship, composite, synonym, deferred, ), ) @overload def mapped_as_dataclass(self, __cls: Type[_O]) -> Type[_O]: ... @overload def mapped_as_dataclass( self, __cls: Literal[None] = ..., *, init: Union[_NoArg, bool] = ..., repr: Union[_NoArg, bool] = ..., # noqa: A002 eq: Union[_NoArg, bool] = ..., order: Union[_NoArg, bool] = ..., unsafe_hash: Union[_NoArg, bool] = ..., match_args: Union[_NoArg, bool] = ..., kw_only: Union[_NoArg, bool] = ..., dataclass_callable: Union[_NoArg, Callable[..., Type[Any]]] = ..., ) -> Callable[[Type[_O]], Type[_O]]: ... def mapped_as_dataclass( self, __cls: Optional[Type[_O]] = None, *, init: Union[_NoArg, bool] = _NoArg.NO_ARG, repr: Union[_NoArg, bool] = _NoArg.NO_ARG, # noqa: A002 eq: Union[_NoArg, bool] = _NoArg.NO_ARG, order: Union[_NoArg, bool] = _NoArg.NO_ARG, unsafe_hash: Union[_NoArg, bool] = _NoArg.NO_ARG, match_args: Union[_NoArg, bool] = _NoArg.NO_ARG, kw_only: Union[_NoArg, bool] = _NoArg.NO_ARG, dataclass_callable: Union[ _NoArg, Callable[..., Type[Any]] ] = _NoArg.NO_ARG, ) -> Union[Type[_O], Callable[[Type[_O]], Type[_O]]]: """Class decorator that will apply the Declarative mapping process to a given class, and additionally convert the class to be a Python dataclass. .. seealso:: :ref:`orm_declarative_native_dataclasses` - complete background on SQLAlchemy native dataclass mapping .. versionadded:: 2.0 """ def decorate(cls: Type[_O]) -> Type[_O]: setattr( cls, "_sa_apply_dc_transforms", { "init": init, "repr": repr, "eq": eq, "order": order, "unsafe_hash": unsafe_hash, "match_args": match_args, "kw_only": kw_only, "dataclass_callable": dataclass_callable, }, ) _as_declarative(self, cls, cls.__dict__) return cls if __cls: return decorate(__cls) else: return decorate def mapped(self, cls: Type[_O]) -> Type[_O]: """Class decorator that will apply the Declarative mapping process to a given class. E.g.:: from sqlalchemy.orm import registry mapper_registry = registry() @mapper_registry.mapped class Foo: __tablename__ = 'some_table' id = Column(Integer, primary_key=True) name = Column(String) See the section :ref:`orm_declarative_mapping` for complete details and examples. :param cls: class to be mapped. :return: the class that was passed. .. seealso:: :ref:`orm_declarative_mapping` :meth:`_orm.registry.generate_base` - generates a base class that will apply Declarative mapping to subclasses automatically using a Python metaclass. .. seealso:: :meth:`_orm.registry.mapped_as_dataclass` """ _as_declarative(self, cls, cls.__dict__) return cls def as_declarative_base(self, **kw: Any) -> Callable[[Type[_T]], Type[_T]]: """ Class decorator which will invoke :meth:`_orm.registry.generate_base` for a given base class. E.g.:: from sqlalchemy.orm import registry mapper_registry = registry() @mapper_registry.as_declarative_base() class Base: @declared_attr def __tablename__(cls): return cls.__name__.lower() id = Column(Integer, primary_key=True) class MyMappedClass(Base): # ... All keyword arguments passed to :meth:`_orm.registry.as_declarative_base` are passed along to :meth:`_orm.registry.generate_base`. """ def decorate(cls: Type[_T]) -> Type[_T]: kw["cls"] = cls kw["name"] = cls.__name__ return self.generate_base(**kw) # type: ignore return decorate def map_declaratively(self, cls: Type[_O]) -> Mapper[_O]: """Map a class declaratively. In this form of mapping, the class is scanned for mapping information, including for columns to be associated with a table, and/or an actual table object. Returns the :class:`_orm.Mapper` object. E.g.:: from sqlalchemy.orm import registry mapper_registry = registry() class Foo: __tablename__ = 'some_table' id = Column(Integer, primary_key=True) name = Column(String) mapper = mapper_registry.map_declaratively(Foo) This function is more conveniently invoked indirectly via either the :meth:`_orm.registry.mapped` class decorator or by subclassing a declarative metaclass generated from :meth:`_orm.registry.generate_base`. See the section :ref:`orm_declarative_mapping` for complete details and examples. :param cls: class to be mapped. :return: a :class:`_orm.Mapper` object. .. seealso:: :ref:`orm_declarative_mapping` :meth:`_orm.registry.mapped` - more common decorator interface to this function. :meth:`_orm.registry.map_imperatively` """ _as_declarative(self, cls, cls.__dict__) return cls.__mapper__ # type: ignore def map_imperatively( self, class_: Type[_O], local_table: Optional[FromClause] = None, **kw: Any, ) -> Mapper[_O]: r"""Map a class imperatively. In this form of mapping, the class is not scanned for any mapping information. Instead, all mapping constructs are passed as arguments. This method is intended to be fully equivalent to the now-removed SQLAlchemy ``mapper()`` function, except that it's in terms of a particular registry. E.g.:: from sqlalchemy.orm import registry mapper_registry = registry() my_table = Table( "my_table", mapper_registry.metadata, Column('id', Integer, primary_key=True) ) class MyClass: pass mapper_registry.map_imperatively(MyClass, my_table) See the section :ref:`orm_imperative_mapping` for complete background and usage examples. :param class\_: The class to be mapped. Corresponds to the :paramref:`_orm.Mapper.class_` parameter. :param local_table: the :class:`_schema.Table` or other :class:`_sql.FromClause` object that is the subject of the mapping. Corresponds to the :paramref:`_orm.Mapper.local_table` parameter. :param \**kw: all other keyword arguments are passed to the :class:`_orm.Mapper` constructor directly. .. seealso:: :ref:`orm_imperative_mapping` :ref:`orm_declarative_mapping` """ return _mapper(self, class_, local_table, kw) RegistryType = registry if not TYPE_CHECKING: # allow for runtime type resolution of ``ClassVar[_RegistryType]`` _RegistryType = registry # noqa def as_declarative(**kw: Any) -> Callable[[Type[_T]], Type[_T]]: """ Class decorator which will adapt a given class into a :func:`_orm.declarative_base`. This function makes use of the :meth:`_orm.registry.as_declarative_base` method, by first creating a :class:`_orm.registry` automatically and then invoking the decorator. E.g.:: from sqlalchemy.orm import as_declarative @as_declarative() class Base: @declared_attr def __tablename__(cls): return cls.__name__.lower() id = Column(Integer, primary_key=True) class MyMappedClass(Base): # ... .. seealso:: :meth:`_orm.registry.as_declarative_base` """ metadata, class_registry = ( kw.pop("metadata", None), kw.pop("class_registry", None), ) return registry( metadata=metadata, class_registry=class_registry ).as_declarative_base(**kw) @inspection._inspects( DeclarativeMeta, DeclarativeBase, DeclarativeAttributeIntercept ) def _inspect_decl_meta(cls: Type[Any]) -> Optional[Mapper[Any]]: mp: Optional[Mapper[Any]] = _inspect_mapped_class(cls) if mp is None: if _DeferredMapperConfig.has_cls(cls): _DeferredMapperConfig.raise_unmapped_for_cls(cls) return mp