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3631 lines
136 KiB
3631 lines
136 KiB
# orm/mapper.py
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# Copyright (C) 2005-2022 the SQLAlchemy authors and contributors
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# <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: https://www.opensource.org/licenses/mit-license.php
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"""Logic to map Python classes to and from selectables.
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Defines the :class:`~sqlalchemy.orm.mapper.Mapper` class, the central
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configurational unit which associates a class with a database table.
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This is a semi-private module; the main configurational API of the ORM is
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available in :class:`~sqlalchemy.orm.`.
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"""
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from __future__ import absolute_import
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from collections import deque
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from itertools import chain
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import sys
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import weakref
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from . import attributes
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from . import exc as orm_exc
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from . import instrumentation
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from . import loading
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from . import properties
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from . import util as orm_util
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from .base import _class_to_mapper
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from .base import _state_mapper
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from .base import class_mapper
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from .base import state_str
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from .interfaces import _MappedAttribute
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from .interfaces import EXT_SKIP
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from .interfaces import InspectionAttr
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from .interfaces import MapperProperty
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from .interfaces import ORMEntityColumnsClauseRole
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from .interfaces import ORMFromClauseRole
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from .interfaces import StrategizedProperty
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from .path_registry import PathRegistry
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from .. import event
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from .. import exc as sa_exc
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from .. import inspection
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from .. import log
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from .. import schema
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from .. import sql
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from .. import util
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from ..sql import base as sql_base
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from ..sql import coercions
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from ..sql import expression
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from ..sql import operators
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from ..sql import roles
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from ..sql import util as sql_util
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from ..sql import visitors
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from ..sql.selectable import LABEL_STYLE_TABLENAME_PLUS_COL
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from ..util import HasMemoized
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_mapper_registries = weakref.WeakKeyDictionary()
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_legacy_registry = None
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def _all_registries():
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with _CONFIGURE_MUTEX:
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return set(_mapper_registries)
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def _unconfigured_mappers():
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for reg in _all_registries():
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for mapper in reg._mappers_to_configure():
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yield mapper
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_already_compiling = False
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# a constant returned by _get_attr_by_column to indicate
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# this mapper is not handling an attribute for a particular
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# column
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NO_ATTRIBUTE = util.symbol("NO_ATTRIBUTE")
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# lock used to synchronize the "mapper configure" step
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_CONFIGURE_MUTEX = util.threading.RLock()
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@inspection._self_inspects
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@log.class_logger
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class Mapper(
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ORMFromClauseRole,
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ORMEntityColumnsClauseRole,
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sql_base.MemoizedHasCacheKey,
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InspectionAttr,
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):
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"""Defines an association between a Python class and a database table or
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other relational structure, so that ORM operations against the class may
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proceed.
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The :class:`_orm.Mapper` object is instantiated using mapping methods
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present on the :class:`_orm.registry` object. For information
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about instantiating new :class:`_orm.Mapper` objects, see
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:ref:`orm_mapping_classes_toplevel`.
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"""
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_dispose_called = False
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_ready_for_configure = False
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@util.deprecated_params(
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non_primary=(
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"1.3",
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"The :paramref:`.mapper.non_primary` parameter is deprecated, "
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"and will be removed in a future release. The functionality "
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"of non primary mappers is now better suited using the "
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":class:`.AliasedClass` construct, which can also be used "
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"as the target of a :func:`_orm.relationship` in 1.3.",
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),
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)
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def __init__(
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self,
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class_,
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local_table=None,
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properties=None,
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primary_key=None,
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non_primary=False,
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inherits=None,
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inherit_condition=None,
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inherit_foreign_keys=None,
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always_refresh=False,
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version_id_col=None,
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version_id_generator=None,
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polymorphic_on=None,
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_polymorphic_map=None,
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polymorphic_identity=None,
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concrete=False,
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with_polymorphic=None,
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polymorphic_load=None,
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allow_partial_pks=True,
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batch=True,
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column_prefix=None,
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include_properties=None,
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exclude_properties=None,
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passive_updates=True,
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passive_deletes=False,
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confirm_deleted_rows=True,
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eager_defaults=False,
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legacy_is_orphan=False,
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_compiled_cache_size=100,
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):
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r"""Direct constructor for a new :class:`_orm.Mapper` object.
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The :func:`_orm.mapper` function is normally invoked through the
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use of the :class:`_orm.registry` object through either the
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:ref:`Declarative <orm_declarative_mapping>` or
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:ref:`Imperative <orm_imperative_mapping>` mapping styles.
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.. versionchanged:: 1.4 The :func:`_orm.mapper` function should not
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be called directly for classical mapping; for a classical mapping
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configuration, use the :meth:`_orm.registry.map_imperatively`
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method. The :func:`_orm.mapper` function may become private in a
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future release.
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Parameters documented below may be passed to either the
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:meth:`_orm.registry.map_imperatively` method, or may be passed in the
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``__mapper_args__`` declarative class attribute described at
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:ref:`orm_declarative_mapper_options`.
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:param class\_: The class to be mapped. When using Declarative,
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this argument is automatically passed as the declared class
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itself.
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:param local_table: The :class:`_schema.Table` or other selectable
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to which the class is mapped. May be ``None`` if
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this mapper inherits from another mapper using single-table
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inheritance. When using Declarative, this argument is
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automatically passed by the extension, based on what
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is configured via the ``__table__`` argument or via the
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:class:`_schema.Table`
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produced as a result of the ``__tablename__``
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and :class:`_schema.Column` arguments present.
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:param always_refresh: If True, all query operations for this mapped
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class will overwrite all data within object instances that already
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exist within the session, erasing any in-memory changes with
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whatever information was loaded from the database. Usage of this
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flag is highly discouraged; as an alternative, see the method
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:meth:`_query.Query.populate_existing`.
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:param allow_partial_pks: Defaults to True. Indicates that a
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composite primary key with some NULL values should be considered as
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possibly existing within the database. This affects whether a
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mapper will assign an incoming row to an existing identity, as well
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as if :meth:`.Session.merge` will check the database first for a
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particular primary key value. A "partial primary key" can occur if
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one has mapped to an OUTER JOIN, for example.
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:param batch: Defaults to ``True``, indicating that save operations
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of multiple entities can be batched together for efficiency.
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Setting to False indicates
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that an instance will be fully saved before saving the next
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instance. This is used in the extremely rare case that a
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:class:`.MapperEvents` listener requires being called
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in between individual row persistence operations.
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:param column_prefix: A string which will be prepended
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to the mapped attribute name when :class:`_schema.Column`
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objects are automatically assigned as attributes to the
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mapped class. Does not affect explicitly specified
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column-based properties.
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See the section :ref:`column_prefix` for an example.
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:param concrete: If True, indicates this mapper should use concrete
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table inheritance with its parent mapper.
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See the section :ref:`concrete_inheritance` for an example.
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:param confirm_deleted_rows: defaults to True; when a DELETE occurs
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of one more rows based on specific primary keys, a warning is
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emitted when the number of rows matched does not equal the number
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of rows expected. This parameter may be set to False to handle the
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case where database ON DELETE CASCADE rules may be deleting some of
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those rows automatically. The warning may be changed to an
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exception in a future release.
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.. versionadded:: 0.9.4 - added
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:paramref:`.mapper.confirm_deleted_rows` as well as conditional
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matched row checking on delete.
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:param eager_defaults: if True, the ORM will immediately fetch the
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value of server-generated default values after an INSERT or UPDATE,
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rather than leaving them as expired to be fetched on next access.
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This can be used for event schemes where the server-generated values
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are needed immediately before the flush completes. By default,
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this scheme will emit an individual ``SELECT`` statement per row
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inserted or updated, which note can add significant performance
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overhead. However, if the
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target database supports :term:`RETURNING`, the default values will
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be returned inline with the INSERT or UPDATE statement, which can
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greatly enhance performance for an application that needs frequent
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access to just-generated server defaults.
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.. seealso::
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:ref:`orm_server_defaults`
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.. versionchanged:: 0.9.0 The ``eager_defaults`` option can now
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make use of :term:`RETURNING` for backends which support it.
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:param exclude_properties: A list or set of string column names to
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be excluded from mapping.
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See :ref:`include_exclude_cols` for an example.
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:param include_properties: An inclusive list or set of string column
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names to map.
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See :ref:`include_exclude_cols` for an example.
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:param inherits: A mapped class or the corresponding
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:class:`_orm.Mapper`
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of one indicating a superclass to which this :class:`_orm.Mapper`
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should *inherit* from. The mapped class here must be a subclass
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of the other mapper's class. When using Declarative, this argument
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is passed automatically as a result of the natural class
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hierarchy of the declared classes.
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.. seealso::
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:ref:`inheritance_toplevel`
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:param inherit_condition: For joined table inheritance, a SQL
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expression which will
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define how the two tables are joined; defaults to a natural join
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between the two tables.
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:param inherit_foreign_keys: When ``inherit_condition`` is used and
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the columns present are missing a :class:`_schema.ForeignKey`
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configuration, this parameter can be used to specify which columns
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are "foreign". In most cases can be left as ``None``.
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:param legacy_is_orphan: Boolean, defaults to ``False``.
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When ``True``, specifies that "legacy" orphan consideration
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is to be applied to objects mapped by this mapper, which means
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that a pending (that is, not persistent) object is auto-expunged
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from an owning :class:`.Session` only when it is de-associated
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from *all* parents that specify a ``delete-orphan`` cascade towards
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this mapper. The new default behavior is that the object is
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auto-expunged when it is de-associated with *any* of its parents
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that specify ``delete-orphan`` cascade. This behavior is more
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consistent with that of a persistent object, and allows behavior to
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be consistent in more scenarios independently of whether or not an
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orphan object has been flushed yet or not.
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See the change note and example at :ref:`legacy_is_orphan_addition`
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for more detail on this change.
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:param non_primary: Specify that this :class:`_orm.Mapper`
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is in addition
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to the "primary" mapper, that is, the one used for persistence.
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The :class:`_orm.Mapper` created here may be used for ad-hoc
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mapping of the class to an alternate selectable, for loading
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only.
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.. seealso::
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:ref:`relationship_aliased_class` - the new pattern that removes
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the need for the :paramref:`_orm.Mapper.non_primary` flag.
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:param passive_deletes: Indicates DELETE behavior of foreign key
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columns when a joined-table inheritance entity is being deleted.
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Defaults to ``False`` for a base mapper; for an inheriting mapper,
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defaults to ``False`` unless the value is set to ``True``
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on the superclass mapper.
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When ``True``, it is assumed that ON DELETE CASCADE is configured
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on the foreign key relationships that link this mapper's table
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to its superclass table, so that when the unit of work attempts
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to delete the entity, it need only emit a DELETE statement for the
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superclass table, and not this table.
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When ``False``, a DELETE statement is emitted for this mapper's
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table individually. If the primary key attributes local to this
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table are unloaded, then a SELECT must be emitted in order to
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validate these attributes; note that the primary key columns
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of a joined-table subclass are not part of the "primary key" of
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the object as a whole.
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Note that a value of ``True`` is **always** forced onto the
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subclass mappers; that is, it's not possible for a superclass
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to specify passive_deletes without this taking effect for
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all subclass mappers.
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.. versionadded:: 1.1
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.. seealso::
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:ref:`passive_deletes` - description of similar feature as
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used with :func:`_orm.relationship`
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:paramref:`.mapper.passive_updates` - supporting ON UPDATE
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CASCADE for joined-table inheritance mappers
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:param passive_updates: Indicates UPDATE behavior of foreign key
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columns when a primary key column changes on a joined-table
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inheritance mapping. Defaults to ``True``.
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When True, it is assumed that ON UPDATE CASCADE is configured on
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the foreign key in the database, and that the database will handle
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propagation of an UPDATE from a source column to dependent columns
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on joined-table rows.
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When False, it is assumed that the database does not enforce
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referential integrity and will not be issuing its own CASCADE
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operation for an update. The unit of work process will
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emit an UPDATE statement for the dependent columns during a
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primary key change.
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.. seealso::
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:ref:`passive_updates` - description of a similar feature as
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used with :func:`_orm.relationship`
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:paramref:`.mapper.passive_deletes` - supporting ON DELETE
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CASCADE for joined-table inheritance mappers
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:param polymorphic_load: Specifies "polymorphic loading" behavior
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for a subclass in an inheritance hierarchy (joined and single
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table inheritance only). Valid values are:
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* "'inline'" - specifies this class should be part of the
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"with_polymorphic" mappers, e.g. its columns will be included
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in a SELECT query against the base.
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* "'selectin'" - specifies that when instances of this class
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are loaded, an additional SELECT will be emitted to retrieve
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the columns specific to this subclass. The SELECT uses
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IN to fetch multiple subclasses at once.
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.. versionadded:: 1.2
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.. seealso::
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:ref:`with_polymorphic_mapper_config`
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:ref:`polymorphic_selectin`
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:param polymorphic_on: Specifies the column, attribute, or
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SQL expression used to determine the target class for an
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incoming row, when inheriting classes are present.
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This value is commonly a :class:`_schema.Column` object that's
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present in the mapped :class:`_schema.Table`::
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class Employee(Base):
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__tablename__ = 'employee'
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id = Column(Integer, primary_key=True)
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discriminator = Column(String(50))
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__mapper_args__ = {
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"polymorphic_on":discriminator,
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"polymorphic_identity":"employee"
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}
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It may also be specified
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as a SQL expression, as in this example where we
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use the :func:`.case` construct to provide a conditional
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approach::
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class Employee(Base):
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__tablename__ = 'employee'
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id = Column(Integer, primary_key=True)
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discriminator = Column(String(50))
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__mapper_args__ = {
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"polymorphic_on":case([
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(discriminator == "EN", "engineer"),
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(discriminator == "MA", "manager"),
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], else_="employee"),
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"polymorphic_identity":"employee"
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}
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It may also refer to any attribute
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configured with :func:`.column_property`, or to the
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string name of one::
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class Employee(Base):
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__tablename__ = 'employee'
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id = Column(Integer, primary_key=True)
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discriminator = Column(String(50))
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employee_type = column_property(
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case([
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(discriminator == "EN", "engineer"),
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(discriminator == "MA", "manager"),
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], else_="employee")
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)
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__mapper_args__ = {
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"polymorphic_on":employee_type,
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"polymorphic_identity":"employee"
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}
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When setting ``polymorphic_on`` to reference an
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attribute or expression that's not present in the
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locally mapped :class:`_schema.Table`, yet the value
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of the discriminator should be persisted to the database,
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the value of the
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discriminator is not automatically set on new
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instances; this must be handled by the user,
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either through manual means or via event listeners.
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A typical approach to establishing such a listener
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looks like::
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from sqlalchemy import event
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from sqlalchemy.orm import object_mapper
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@event.listens_for(Employee, "init", propagate=True)
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def set_identity(instance, *arg, **kw):
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mapper = object_mapper(instance)
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instance.discriminator = mapper.polymorphic_identity
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Where above, we assign the value of ``polymorphic_identity``
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for the mapped class to the ``discriminator`` attribute,
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thus persisting the value to the ``discriminator`` column
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in the database.
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.. warning::
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Currently, **only one discriminator column may be set**, typically
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on the base-most class in the hierarchy. "Cascading" polymorphic
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columns are not yet supported.
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.. seealso::
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|
:ref:`inheritance_toplevel`
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:param polymorphic_identity: Specifies the value which
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identifies this particular class as returned by the
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column expression referred to by the ``polymorphic_on``
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setting. As rows are received, the value corresponding
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to the ``polymorphic_on`` column expression is compared
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to this value, indicating which subclass should
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be used for the newly reconstructed object.
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:param properties: A dictionary mapping the string names of object
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attributes to :class:`.MapperProperty` instances, which define the
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persistence behavior of that attribute. Note that
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:class:`_schema.Column`
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objects present in
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the mapped :class:`_schema.Table` are automatically placed into
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``ColumnProperty`` instances upon mapping, unless overridden.
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When using Declarative, this argument is passed automatically,
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based on all those :class:`.MapperProperty` instances declared
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in the declared class body.
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:param primary_key: A list of :class:`_schema.Column`
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objects which define
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the primary key to be used against this mapper's selectable unit.
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This is normally simply the primary key of the ``local_table``, but
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can be overridden here.
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:param version_id_col: A :class:`_schema.Column`
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that will be used to keep a running version id of rows
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in the table. This is used to detect concurrent updates or
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the presence of stale data in a flush. The methodology is to
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detect if an UPDATE statement does not match the last known
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version id, a
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:class:`~sqlalchemy.orm.exc.StaleDataError` exception is
|
|
thrown.
|
|
By default, the column must be of :class:`.Integer` type,
|
|
unless ``version_id_generator`` specifies an alternative version
|
|
generator.
|
|
|
|
.. seealso::
|
|
|
|
:ref:`mapper_version_counter` - discussion of version counting
|
|
and rationale.
|
|
|
|
:param version_id_generator: Define how new version ids should
|
|
be generated. Defaults to ``None``, which indicates that
|
|
a simple integer counting scheme be employed. To provide a custom
|
|
versioning scheme, provide a callable function of the form::
|
|
|
|
def generate_version(version):
|
|
return next_version
|
|
|
|
Alternatively, server-side versioning functions such as triggers,
|
|
or programmatic versioning schemes outside of the version id
|
|
generator may be used, by specifying the value ``False``.
|
|
Please see :ref:`server_side_version_counter` for a discussion
|
|
of important points when using this option.
|
|
|
|
.. versionadded:: 0.9.0 ``version_id_generator`` supports
|
|
server-side version number generation.
|
|
|
|
.. seealso::
|
|
|
|
:ref:`custom_version_counter`
|
|
|
|
:ref:`server_side_version_counter`
|
|
|
|
|
|
:param with_polymorphic: A tuple in the form ``(<classes>,
|
|
<selectable>)`` indicating the default style of "polymorphic"
|
|
loading, that is, which tables are queried at once. <classes> is
|
|
any single or list of mappers and/or classes indicating the
|
|
inherited classes that should be loaded at once. The special value
|
|
``'*'`` may be used to indicate all descending classes should be
|
|
loaded immediately. The second tuple argument <selectable>
|
|
indicates a selectable that will be used to query for multiple
|
|
classes.
|
|
|
|
.. seealso::
|
|
|
|
:ref:`with_polymorphic` - discussion of polymorphic querying
|
|
techniques.
|
|
|
|
"""
|
|
self.class_ = util.assert_arg_type(class_, type, "class_")
|
|
self._sort_key = "%s.%s" % (
|
|
self.class_.__module__,
|
|
self.class_.__name__,
|
|
)
|
|
|
|
self.class_manager = None
|
|
|
|
self._primary_key_argument = util.to_list(primary_key)
|
|
self.non_primary = non_primary
|
|
|
|
self.always_refresh = always_refresh
|
|
|
|
if isinstance(version_id_col, MapperProperty):
|
|
self.version_id_prop = version_id_col
|
|
self.version_id_col = None
|
|
else:
|
|
self.version_id_col = version_id_col
|
|
if version_id_generator is False:
|
|
self.version_id_generator = False
|
|
elif version_id_generator is None:
|
|
self.version_id_generator = lambda x: (x or 0) + 1
|
|
else:
|
|
self.version_id_generator = version_id_generator
|
|
|
|
self.concrete = concrete
|
|
self.single = False
|
|
self.inherits = inherits
|
|
if local_table is not None:
|
|
self.local_table = coercions.expect(
|
|
roles.StrictFromClauseRole, local_table
|
|
)
|
|
else:
|
|
self.local_table = None
|
|
|
|
self.inherit_condition = inherit_condition
|
|
self.inherit_foreign_keys = inherit_foreign_keys
|
|
self._init_properties = properties or {}
|
|
self._delete_orphans = []
|
|
self.batch = batch
|
|
self.eager_defaults = eager_defaults
|
|
self.column_prefix = column_prefix
|
|
self.polymorphic_on = (
|
|
coercions.expect(
|
|
roles.ColumnArgumentOrKeyRole,
|
|
polymorphic_on,
|
|
argname="polymorphic_on",
|
|
)
|
|
if polymorphic_on is not None
|
|
else None
|
|
)
|
|
self._dependency_processors = []
|
|
self.validators = util.EMPTY_DICT
|
|
self.passive_updates = passive_updates
|
|
self.passive_deletes = passive_deletes
|
|
self.legacy_is_orphan = legacy_is_orphan
|
|
self._clause_adapter = None
|
|
self._requires_row_aliasing = False
|
|
self._inherits_equated_pairs = None
|
|
self._memoized_values = {}
|
|
self._compiled_cache_size = _compiled_cache_size
|
|
self._reconstructor = None
|
|
self.allow_partial_pks = allow_partial_pks
|
|
|
|
if self.inherits and not self.concrete:
|
|
self.confirm_deleted_rows = False
|
|
else:
|
|
self.confirm_deleted_rows = confirm_deleted_rows
|
|
|
|
self._set_with_polymorphic(with_polymorphic)
|
|
self.polymorphic_load = polymorphic_load
|
|
|
|
# our 'polymorphic identity', a string name that when located in a
|
|
# result set row indicates this Mapper should be used to construct
|
|
# the object instance for that row.
|
|
self.polymorphic_identity = polymorphic_identity
|
|
|
|
# a dictionary of 'polymorphic identity' names, associating those
|
|
# names with Mappers that will be used to construct object instances
|
|
# upon a select operation.
|
|
if _polymorphic_map is None:
|
|
self.polymorphic_map = {}
|
|
else:
|
|
self.polymorphic_map = _polymorphic_map
|
|
|
|
if include_properties is not None:
|
|
self.include_properties = util.to_set(include_properties)
|
|
else:
|
|
self.include_properties = None
|
|
if exclude_properties:
|
|
self.exclude_properties = util.to_set(exclude_properties)
|
|
else:
|
|
self.exclude_properties = None
|
|
|
|
# prevent this mapper from being constructed
|
|
# while a configure_mappers() is occurring (and defer a
|
|
# configure_mappers() until construction succeeds)
|
|
with _CONFIGURE_MUTEX:
|
|
self.dispatch._events._new_mapper_instance(class_, self)
|
|
self._configure_inheritance()
|
|
self._configure_class_instrumentation()
|
|
self._configure_properties()
|
|
self._configure_polymorphic_setter()
|
|
self._configure_pks()
|
|
self.registry._flag_new_mapper(self)
|
|
self._log("constructed")
|
|
self._expire_memoizations()
|
|
|
|
# major attributes initialized at the classlevel so that
|
|
# they can be Sphinx-documented.
|
|
|
|
is_mapper = True
|
|
"""Part of the inspection API."""
|
|
|
|
represents_outer_join = False
|
|
|
|
@property
|
|
def mapper(self):
|
|
"""Part of the inspection API.
|
|
|
|
Returns self.
|
|
|
|
"""
|
|
return self
|
|
|
|
def _gen_cache_key(self, anon_map, bindparams):
|
|
return (self,)
|
|
|
|
@property
|
|
def entity(self):
|
|
r"""Part of the inspection API.
|
|
|
|
Returns self.class\_.
|
|
|
|
"""
|
|
return self.class_
|
|
|
|
local_table = None
|
|
"""The :class:`_expression.Selectable` which this :class:`_orm.Mapper`
|
|
manages.
|
|
|
|
Typically is an instance of :class:`_schema.Table` or
|
|
:class:`_expression.Alias`.
|
|
May also be ``None``.
|
|
|
|
The "local" table is the
|
|
selectable that the :class:`_orm.Mapper` is directly responsible for
|
|
managing from an attribute access and flush perspective. For
|
|
non-inheriting mappers, the local table is the same as the
|
|
"mapped" table. For joined-table inheritance mappers, local_table
|
|
will be the particular sub-table of the overall "join" which
|
|
this :class:`_orm.Mapper` represents. If this mapper is a
|
|
single-table inheriting mapper, local_table will be ``None``.
|
|
|
|
.. seealso::
|
|
|
|
:attr:`_orm.Mapper.persist_selectable`.
|
|
|
|
"""
|
|
|
|
persist_selectable = None
|
|
"""The :class:`_expression.Selectable` to which this :class:`_orm.Mapper`
|
|
is mapped.
|
|
|
|
Typically an instance of :class:`_schema.Table`,
|
|
:class:`_expression.Join`, or :class:`_expression.Alias`.
|
|
|
|
The :attr:`_orm.Mapper.persist_selectable` is separate from
|
|
:attr:`_orm.Mapper.selectable` in that the former represents columns
|
|
that are mapped on this class or its superclasses, whereas the
|
|
latter may be a "polymorphic" selectable that contains additional columns
|
|
which are in fact mapped on subclasses only.
|
|
|
|
"persist selectable" is the "thing the mapper writes to" and
|
|
"selectable" is the "thing the mapper selects from".
|
|
|
|
:attr:`_orm.Mapper.persist_selectable` is also separate from
|
|
:attr:`_orm.Mapper.local_table`, which represents the set of columns that
|
|
are locally mapped on this class directly.
|
|
|
|
|
|
.. seealso::
|
|
|
|
:attr:`_orm.Mapper.selectable`.
|
|
|
|
:attr:`_orm.Mapper.local_table`.
|
|
|
|
"""
|
|
|
|
inherits = None
|
|
"""References the :class:`_orm.Mapper` which this :class:`_orm.Mapper`
|
|
inherits from, if any.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
"""
|
|
|
|
configured = False
|
|
"""Represent ``True`` if this :class:`_orm.Mapper` has been configured.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
.. seealso::
|
|
|
|
:func:`.configure_mappers`.
|
|
|
|
"""
|
|
|
|
concrete = None
|
|
"""Represent ``True`` if this :class:`_orm.Mapper` is a concrete
|
|
inheritance mapper.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
"""
|
|
|
|
tables = None
|
|
"""An iterable containing the collection of :class:`_schema.Table` objects
|
|
which this :class:`_orm.Mapper` is aware of.
|
|
|
|
If the mapper is mapped to a :class:`_expression.Join`, or an
|
|
:class:`_expression.Alias`
|
|
representing a :class:`_expression.Select`, the individual
|
|
:class:`_schema.Table`
|
|
objects that comprise the full construct will be represented here.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
"""
|
|
|
|
primary_key = None
|
|
"""An iterable containing the collection of :class:`_schema.Column`
|
|
objects
|
|
which comprise the 'primary key' of the mapped table, from the
|
|
perspective of this :class:`_orm.Mapper`.
|
|
|
|
This list is against the selectable in
|
|
:attr:`_orm.Mapper.persist_selectable`.
|
|
In the case of inheriting mappers, some columns may be managed by a
|
|
superclass mapper. For example, in the case of a
|
|
:class:`_expression.Join`, the
|
|
primary key is determined by all of the primary key columns across all
|
|
tables referenced by the :class:`_expression.Join`.
|
|
|
|
The list is also not necessarily the same as the primary key column
|
|
collection associated with the underlying tables; the :class:`_orm.Mapper`
|
|
features a ``primary_key`` argument that can override what the
|
|
:class:`_orm.Mapper` considers as primary key columns.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
"""
|
|
|
|
class_ = None
|
|
"""The Python class which this :class:`_orm.Mapper` maps.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
"""
|
|
|
|
class_manager = None
|
|
"""The :class:`.ClassManager` which maintains event listeners
|
|
and class-bound descriptors for this :class:`_orm.Mapper`.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
"""
|
|
|
|
single = None
|
|
"""Represent ``True`` if this :class:`_orm.Mapper` is a single table
|
|
inheritance mapper.
|
|
|
|
:attr:`_orm.Mapper.local_table` will be ``None`` if this flag is set.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
"""
|
|
|
|
non_primary = None
|
|
"""Represent ``True`` if this :class:`_orm.Mapper` is a "non-primary"
|
|
mapper, e.g. a mapper that is used only to select rows but not for
|
|
persistence management.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
"""
|
|
|
|
polymorphic_on = None
|
|
"""The :class:`_schema.Column` or SQL expression specified as the
|
|
``polymorphic_on`` argument
|
|
for this :class:`_orm.Mapper`, within an inheritance scenario.
|
|
|
|
This attribute is normally a :class:`_schema.Column` instance but
|
|
may also be an expression, such as one derived from
|
|
:func:`.cast`.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
"""
|
|
|
|
polymorphic_map = None
|
|
"""A mapping of "polymorphic identity" identifiers mapped to
|
|
:class:`_orm.Mapper` instances, within an inheritance scenario.
|
|
|
|
The identifiers can be of any type which is comparable to the
|
|
type of column represented by :attr:`_orm.Mapper.polymorphic_on`.
|
|
|
|
An inheritance chain of mappers will all reference the same
|
|
polymorphic map object. The object is used to correlate incoming
|
|
result rows to target mappers.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
"""
|
|
|
|
polymorphic_identity = None
|
|
"""Represent an identifier which is matched against the
|
|
:attr:`_orm.Mapper.polymorphic_on` column during result row loading.
|
|
|
|
Used only with inheritance, this object can be of any type which is
|
|
comparable to the type of column represented by
|
|
:attr:`_orm.Mapper.polymorphic_on`.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
"""
|
|
|
|
base_mapper = None
|
|
"""The base-most :class:`_orm.Mapper` in an inheritance chain.
|
|
|
|
In a non-inheriting scenario, this attribute will always be this
|
|
:class:`_orm.Mapper`. In an inheritance scenario, it references
|
|
the :class:`_orm.Mapper` which is parent to all other :class:`_orm.Mapper`
|
|
objects in the inheritance chain.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
"""
|
|
|
|
columns = None
|
|
"""A collection of :class:`_schema.Column` or other scalar expression
|
|
objects maintained by this :class:`_orm.Mapper`.
|
|
|
|
The collection behaves the same as that of the ``c`` attribute on
|
|
any :class:`_schema.Table` object,
|
|
except that only those columns included in
|
|
this mapping are present, and are keyed based on the attribute name
|
|
defined in the mapping, not necessarily the ``key`` attribute of the
|
|
:class:`_schema.Column` itself. Additionally, scalar expressions mapped
|
|
by :func:`.column_property` are also present here.
|
|
|
|
This is a *read only* attribute determined during mapper construction.
|
|
Behavior is undefined if directly modified.
|
|
|
|
"""
|
|
|
|
validators = None
|
|
"""An immutable dictionary of attributes which have been decorated
|
|
using the :func:`_orm.validates` decorator.
|
|
|
|
The dictionary contains string attribute names as keys
|
|
mapped to the actual validation method.
|
|
|
|
"""
|
|
|
|
c = None
|
|
"""A synonym for :attr:`_orm.Mapper.columns`."""
|
|
|
|
@property
|
|
@util.deprecated("1.3", "Use .persist_selectable")
|
|
def mapped_table(self):
|
|
return self.persist_selectable
|
|
|
|
@util.memoized_property
|
|
def _path_registry(self):
|
|
return PathRegistry.per_mapper(self)
|
|
|
|
def _configure_inheritance(self):
|
|
"""Configure settings related to inheriting and/or inherited mappers
|
|
being present."""
|
|
|
|
# a set of all mappers which inherit from this one.
|
|
self._inheriting_mappers = util.WeakSequence()
|
|
|
|
if self.inherits:
|
|
if isinstance(self.inherits, type):
|
|
self.inherits = class_mapper(self.inherits, configure=False)
|
|
if not issubclass(self.class_, self.inherits.class_):
|
|
raise sa_exc.ArgumentError(
|
|
"Class '%s' does not inherit from '%s'"
|
|
% (self.class_.__name__, self.inherits.class_.__name__)
|
|
)
|
|
|
|
self.dispatch._update(self.inherits.dispatch)
|
|
|
|
if self.non_primary != self.inherits.non_primary:
|
|
np = not self.non_primary and "primary" or "non-primary"
|
|
raise sa_exc.ArgumentError(
|
|
"Inheritance of %s mapper for class '%s' is "
|
|
"only allowed from a %s mapper"
|
|
% (np, self.class_.__name__, np)
|
|
)
|
|
# inherit_condition is optional.
|
|
if self.local_table is None:
|
|
self.local_table = self.inherits.local_table
|
|
self.persist_selectable = self.inherits.persist_selectable
|
|
self.single = True
|
|
elif self.local_table is not self.inherits.local_table:
|
|
if self.concrete:
|
|
self.persist_selectable = self.local_table
|
|
for mapper in self.iterate_to_root():
|
|
if mapper.polymorphic_on is not None:
|
|
mapper._requires_row_aliasing = True
|
|
else:
|
|
if self.inherit_condition is None:
|
|
# figure out inherit condition from our table to the
|
|
# immediate table of the inherited mapper, not its
|
|
# full table which could pull in other stuff we don't
|
|
# want (allows test/inheritance.InheritTest4 to pass)
|
|
try:
|
|
self.inherit_condition = sql_util.join_condition(
|
|
self.inherits.local_table, self.local_table
|
|
)
|
|
except sa_exc.NoForeignKeysError as nfe:
|
|
assert self.inherits.local_table is not None
|
|
assert self.local_table is not None
|
|
util.raise_(
|
|
sa_exc.NoForeignKeysError(
|
|
"Can't determine the inherit condition "
|
|
"between inherited table '%s' and "
|
|
"inheriting "
|
|
"table '%s'; tables have no "
|
|
"foreign key relationships established. "
|
|
"Please ensure the inheriting table has "
|
|
"a foreign key relationship to the "
|
|
"inherited "
|
|
"table, or provide an "
|
|
"'on clause' using "
|
|
"the 'inherit_condition' mapper argument."
|
|
% (
|
|
self.inherits.local_table.description,
|
|
self.local_table.description,
|
|
)
|
|
),
|
|
replace_context=nfe,
|
|
)
|
|
except sa_exc.AmbiguousForeignKeysError as afe:
|
|
assert self.inherits.local_table is not None
|
|
assert self.local_table is not None
|
|
util.raise_(
|
|
sa_exc.AmbiguousForeignKeysError(
|
|
"Can't determine the inherit condition "
|
|
"between inherited table '%s' and "
|
|
"inheriting "
|
|
"table '%s'; tables have more than one "
|
|
"foreign key relationship established. "
|
|
"Please specify the 'on clause' using "
|
|
"the 'inherit_condition' mapper argument."
|
|
% (
|
|
self.inherits.local_table.description,
|
|
self.local_table.description,
|
|
)
|
|
),
|
|
replace_context=afe,
|
|
)
|
|
self.persist_selectable = sql.join(
|
|
self.inherits.persist_selectable,
|
|
self.local_table,
|
|
self.inherit_condition,
|
|
)
|
|
|
|
fks = util.to_set(self.inherit_foreign_keys)
|
|
self._inherits_equated_pairs = sql_util.criterion_as_pairs(
|
|
self.persist_selectable.onclause,
|
|
consider_as_foreign_keys=fks,
|
|
)
|
|
else:
|
|
self.persist_selectable = self.local_table
|
|
|
|
if self.polymorphic_identity is not None and not self.concrete:
|
|
self._identity_class = self.inherits._identity_class
|
|
else:
|
|
self._identity_class = self.class_
|
|
|
|
if self.version_id_col is None:
|
|
self.version_id_col = self.inherits.version_id_col
|
|
self.version_id_generator = self.inherits.version_id_generator
|
|
elif (
|
|
self.inherits.version_id_col is not None
|
|
and self.version_id_col is not self.inherits.version_id_col
|
|
):
|
|
util.warn(
|
|
"Inheriting version_id_col '%s' does not match inherited "
|
|
"version_id_col '%s' and will not automatically populate "
|
|
"the inherited versioning column. "
|
|
"version_id_col should only be specified on "
|
|
"the base-most mapper that includes versioning."
|
|
% (
|
|
self.version_id_col.description,
|
|
self.inherits.version_id_col.description,
|
|
)
|
|
)
|
|
|
|
self.polymorphic_map = self.inherits.polymorphic_map
|
|
self.batch = self.inherits.batch
|
|
self.inherits._inheriting_mappers.append(self)
|
|
self.base_mapper = self.inherits.base_mapper
|
|
self.passive_updates = self.inherits.passive_updates
|
|
self.passive_deletes = (
|
|
self.inherits.passive_deletes or self.passive_deletes
|
|
)
|
|
self._all_tables = self.inherits._all_tables
|
|
|
|
if self.polymorphic_identity is not None:
|
|
if self.polymorphic_identity in self.polymorphic_map:
|
|
util.warn(
|
|
"Reassigning polymorphic association for identity %r "
|
|
"from %r to %r: Check for duplicate use of %r as "
|
|
"value for polymorphic_identity."
|
|
% (
|
|
self.polymorphic_identity,
|
|
self.polymorphic_map[self.polymorphic_identity],
|
|
self,
|
|
self.polymorphic_identity,
|
|
)
|
|
)
|
|
self.polymorphic_map[self.polymorphic_identity] = self
|
|
|
|
if self.polymorphic_load and self.concrete:
|
|
raise sa_exc.ArgumentError(
|
|
"polymorphic_load is not currently supported "
|
|
"with concrete table inheritance"
|
|
)
|
|
if self.polymorphic_load == "inline":
|
|
self.inherits._add_with_polymorphic_subclass(self)
|
|
elif self.polymorphic_load == "selectin":
|
|
pass
|
|
elif self.polymorphic_load is not None:
|
|
raise sa_exc.ArgumentError(
|
|
"unknown argument for polymorphic_load: %r"
|
|
% self.polymorphic_load
|
|
)
|
|
|
|
else:
|
|
self._all_tables = set()
|
|
self.base_mapper = self
|
|
self.persist_selectable = self.local_table
|
|
if self.polymorphic_identity is not None:
|
|
self.polymorphic_map[self.polymorphic_identity] = self
|
|
self._identity_class = self.class_
|
|
|
|
if self.persist_selectable is None:
|
|
raise sa_exc.ArgumentError(
|
|
"Mapper '%s' does not have a persist_selectable specified."
|
|
% self
|
|
)
|
|
|
|
def _set_with_polymorphic(self, with_polymorphic):
|
|
if with_polymorphic == "*":
|
|
self.with_polymorphic = ("*", None)
|
|
elif isinstance(with_polymorphic, (tuple, list)):
|
|
if isinstance(
|
|
with_polymorphic[0], util.string_types + (tuple, list)
|
|
):
|
|
self.with_polymorphic = with_polymorphic
|
|
else:
|
|
self.with_polymorphic = (with_polymorphic, None)
|
|
elif with_polymorphic is not None:
|
|
raise sa_exc.ArgumentError("Invalid setting for with_polymorphic")
|
|
else:
|
|
self.with_polymorphic = None
|
|
|
|
if self.with_polymorphic and self.with_polymorphic[1] is not None:
|
|
self.with_polymorphic = (
|
|
self.with_polymorphic[0],
|
|
coercions.expect(
|
|
roles.StrictFromClauseRole,
|
|
self.with_polymorphic[1],
|
|
allow_select=True,
|
|
),
|
|
)
|
|
|
|
if self.configured:
|
|
self._expire_memoizations()
|
|
|
|
def _add_with_polymorphic_subclass(self, mapper):
|
|
subcl = mapper.class_
|
|
if self.with_polymorphic is None:
|
|
self._set_with_polymorphic((subcl,))
|
|
elif self.with_polymorphic[0] != "*":
|
|
self._set_with_polymorphic(
|
|
(self.with_polymorphic[0] + (subcl,), self.with_polymorphic[1])
|
|
)
|
|
|
|
def _set_concrete_base(self, mapper):
|
|
"""Set the given :class:`_orm.Mapper` as the 'inherits' for this
|
|
:class:`_orm.Mapper`, assuming this :class:`_orm.Mapper` is concrete
|
|
and does not already have an inherits."""
|
|
|
|
assert self.concrete
|
|
assert not self.inherits
|
|
assert isinstance(mapper, Mapper)
|
|
self.inherits = mapper
|
|
self.inherits.polymorphic_map.update(self.polymorphic_map)
|
|
self.polymorphic_map = self.inherits.polymorphic_map
|
|
for mapper in self.iterate_to_root():
|
|
if mapper.polymorphic_on is not None:
|
|
mapper._requires_row_aliasing = True
|
|
self.batch = self.inherits.batch
|
|
for mp in self.self_and_descendants:
|
|
mp.base_mapper = self.inherits.base_mapper
|
|
self.inherits._inheriting_mappers.append(self)
|
|
self.passive_updates = self.inherits.passive_updates
|
|
self._all_tables = self.inherits._all_tables
|
|
|
|
for key, prop in mapper._props.items():
|
|
if key not in self._props and not self._should_exclude(
|
|
key, key, local=False, column=None
|
|
):
|
|
self._adapt_inherited_property(key, prop, False)
|
|
|
|
def _set_polymorphic_on(self, polymorphic_on):
|
|
self.polymorphic_on = polymorphic_on
|
|
self._configure_polymorphic_setter(True)
|
|
|
|
def _configure_class_instrumentation(self):
|
|
"""If this mapper is to be a primary mapper (i.e. the
|
|
non_primary flag is not set), associate this Mapper with the
|
|
given class and entity name.
|
|
|
|
Subsequent calls to ``class_mapper()`` for the ``class_`` / ``entity``
|
|
name combination will return this mapper. Also decorate the
|
|
`__init__` method on the mapped class to include optional
|
|
auto-session attachment logic.
|
|
|
|
"""
|
|
|
|
# we expect that declarative has applied the class manager
|
|
# already and set up a registry. if this is None,
|
|
# we will emit a deprecation warning below when we also see that
|
|
# it has no registry.
|
|
manager = attributes.manager_of_class(self.class_)
|
|
|
|
if self.non_primary:
|
|
if not manager or not manager.is_mapped:
|
|
raise sa_exc.InvalidRequestError(
|
|
"Class %s has no primary mapper configured. Configure "
|
|
"a primary mapper first before setting up a non primary "
|
|
"Mapper." % self.class_
|
|
)
|
|
self.class_manager = manager
|
|
self.registry = manager.registry
|
|
self._identity_class = manager.mapper._identity_class
|
|
manager.registry._add_non_primary_mapper(self)
|
|
return
|
|
|
|
if manager is not None:
|
|
assert manager.class_ is self.class_
|
|
if manager.is_mapped:
|
|
# changed in #7579:
|
|
# this message is defined in two places as of this change,
|
|
# also in decl_api -> _add_manager(). in 2.0, this codepath
|
|
# is removed as any calls to mapper() / Mapper without
|
|
# the registry setting up first will be rejected.
|
|
raise sa_exc.ArgumentError(
|
|
"Class '%s' already has a primary mapper defined. "
|
|
% self.class_
|
|
)
|
|
# else:
|
|
# a ClassManager may already exist as
|
|
# ClassManager.instrument_attribute() creates
|
|
# new managers for each subclass if they don't yet exist.
|
|
|
|
self.dispatch.instrument_class(self, self.class_)
|
|
|
|
# this invokes the class_instrument event and sets up
|
|
# the __init__ method. documented behavior is that this must
|
|
# occur after the instrument_class event above.
|
|
# yes two events with the same two words reversed and different APIs.
|
|
# :(
|
|
|
|
manager = instrumentation.register_class(
|
|
self.class_,
|
|
mapper=self,
|
|
expired_attribute_loader=util.partial(
|
|
loading.load_scalar_attributes, self
|
|
),
|
|
# finalize flag means instrument the __init__ method
|
|
# and call the class_instrument event
|
|
finalize=True,
|
|
)
|
|
|
|
if not manager.registry:
|
|
util.warn_deprecated_20(
|
|
"Calling the mapper() function directly outside of a "
|
|
"declarative registry is deprecated."
|
|
" Please use the sqlalchemy.orm.registry.map_imperatively() "
|
|
"function for a classical mapping."
|
|
)
|
|
assert _legacy_registry is not None
|
|
_legacy_registry._add_manager(manager)
|
|
|
|
self.class_manager = manager
|
|
self.registry = manager.registry
|
|
|
|
# The remaining members can be added by any mapper,
|
|
# e_name None or not.
|
|
if manager.mapper is None:
|
|
return
|
|
|
|
event.listen(manager, "init", _event_on_init, raw=True)
|
|
|
|
for key, method in util.iterate_attributes(self.class_):
|
|
if key == "__init__" and hasattr(method, "_sa_original_init"):
|
|
method = method._sa_original_init
|
|
if hasattr(method, "__func__"):
|
|
method = method.__func__
|
|
if callable(method):
|
|
if hasattr(method, "__sa_reconstructor__"):
|
|
self._reconstructor = method
|
|
event.listen(manager, "load", _event_on_load, raw=True)
|
|
elif hasattr(method, "__sa_validators__"):
|
|
validation_opts = method.__sa_validation_opts__
|
|
for name in method.__sa_validators__:
|
|
if name in self.validators:
|
|
raise sa_exc.InvalidRequestError(
|
|
"A validation function for mapped "
|
|
"attribute %r on mapper %s already exists."
|
|
% (name, self)
|
|
)
|
|
self.validators = self.validators.union(
|
|
{name: (method, validation_opts)}
|
|
)
|
|
|
|
def _set_dispose_flags(self):
|
|
self.configured = True
|
|
self._ready_for_configure = True
|
|
self._dispose_called = True
|
|
|
|
self.__dict__.pop("_configure_failed", None)
|
|
|
|
def _configure_pks(self):
|
|
self.tables = sql_util.find_tables(self.persist_selectable)
|
|
|
|
self._pks_by_table = {}
|
|
self._cols_by_table = {}
|
|
|
|
all_cols = util.column_set(
|
|
chain(*[col.proxy_set for col in self._columntoproperty])
|
|
)
|
|
|
|
pk_cols = util.column_set(c for c in all_cols if c.primary_key)
|
|
|
|
# identify primary key columns which are also mapped by this mapper.
|
|
tables = set(self.tables + [self.persist_selectable])
|
|
self._all_tables.update(tables)
|
|
for t in tables:
|
|
if t.primary_key and pk_cols.issuperset(t.primary_key):
|
|
# ordering is important since it determines the ordering of
|
|
# mapper.primary_key (and therefore query.get())
|
|
self._pks_by_table[t] = util.ordered_column_set(
|
|
t.primary_key
|
|
).intersection(pk_cols)
|
|
self._cols_by_table[t] = util.ordered_column_set(t.c).intersection(
|
|
all_cols
|
|
)
|
|
|
|
# if explicit PK argument sent, add those columns to the
|
|
# primary key mappings
|
|
if self._primary_key_argument:
|
|
for k in self._primary_key_argument:
|
|
if k.table not in self._pks_by_table:
|
|
self._pks_by_table[k.table] = util.OrderedSet()
|
|
self._pks_by_table[k.table].add(k)
|
|
|
|
# otherwise, see that we got a full PK for the mapped table
|
|
elif (
|
|
self.persist_selectable not in self._pks_by_table
|
|
or len(self._pks_by_table[self.persist_selectable]) == 0
|
|
):
|
|
raise sa_exc.ArgumentError(
|
|
"Mapper %s could not assemble any primary "
|
|
"key columns for mapped table '%s'"
|
|
% (self, self.persist_selectable.description)
|
|
)
|
|
elif self.local_table not in self._pks_by_table and isinstance(
|
|
self.local_table, schema.Table
|
|
):
|
|
util.warn(
|
|
"Could not assemble any primary "
|
|
"keys for locally mapped table '%s' - "
|
|
"no rows will be persisted in this Table."
|
|
% self.local_table.description
|
|
)
|
|
|
|
if (
|
|
self.inherits
|
|
and not self.concrete
|
|
and not self._primary_key_argument
|
|
):
|
|
# if inheriting, the "primary key" for this mapper is
|
|
# that of the inheriting (unless concrete or explicit)
|
|
self.primary_key = self.inherits.primary_key
|
|
else:
|
|
# determine primary key from argument or persist_selectable pks
|
|
if self._primary_key_argument:
|
|
primary_key = [
|
|
self.persist_selectable.corresponding_column(c)
|
|
for c in self._primary_key_argument
|
|
]
|
|
else:
|
|
# if heuristically determined PKs, reduce to the minimal set
|
|
# of columns by eliminating FK->PK pairs for a multi-table
|
|
# expression. May over-reduce for some kinds of UNIONs
|
|
# / CTEs; use explicit PK argument for these special cases
|
|
primary_key = sql_util.reduce_columns(
|
|
self._pks_by_table[self.persist_selectable],
|
|
ignore_nonexistent_tables=True,
|
|
)
|
|
|
|
if len(primary_key) == 0:
|
|
raise sa_exc.ArgumentError(
|
|
"Mapper %s could not assemble any primary "
|
|
"key columns for mapped table '%s'"
|
|
% (self, self.persist_selectable.description)
|
|
)
|
|
|
|
self.primary_key = tuple(primary_key)
|
|
self._log("Identified primary key columns: %s", primary_key)
|
|
|
|
# determine cols that aren't expressed within our tables; mark these
|
|
# as "read only" properties which are refreshed upon INSERT/UPDATE
|
|
self._readonly_props = set(
|
|
self._columntoproperty[col]
|
|
for col in self._columntoproperty
|
|
if self._columntoproperty[col] not in self._identity_key_props
|
|
and (
|
|
not hasattr(col, "table")
|
|
or col.table not in self._cols_by_table
|
|
)
|
|
)
|
|
|
|
def _configure_properties(self):
|
|
|
|
# TODO: consider using DedupeColumnCollection
|
|
self.columns = self.c = sql_base.ColumnCollection()
|
|
|
|
# object attribute names mapped to MapperProperty objects
|
|
self._props = util.OrderedDict()
|
|
|
|
# table columns mapped to MapperProperty
|
|
self._columntoproperty = _ColumnMapping(self)
|
|
|
|
# load custom properties
|
|
if self._init_properties:
|
|
for key, prop in self._init_properties.items():
|
|
self._configure_property(key, prop, False)
|
|
|
|
# pull properties from the inherited mapper if any.
|
|
if self.inherits:
|
|
for key, prop in self.inherits._props.items():
|
|
if key not in self._props and not self._should_exclude(
|
|
key, key, local=False, column=None
|
|
):
|
|
self._adapt_inherited_property(key, prop, False)
|
|
|
|
# create properties for each column in the mapped table,
|
|
# for those columns which don't already map to a property
|
|
for column in self.persist_selectable.columns:
|
|
if column in self._columntoproperty:
|
|
continue
|
|
|
|
column_key = (self.column_prefix or "") + column.key
|
|
|
|
if self._should_exclude(
|
|
column.key,
|
|
column_key,
|
|
local=self.local_table.c.contains_column(column),
|
|
column=column,
|
|
):
|
|
continue
|
|
|
|
# adjust the "key" used for this column to that
|
|
# of the inheriting mapper
|
|
for mapper in self.iterate_to_root():
|
|
if column in mapper._columntoproperty:
|
|
column_key = mapper._columntoproperty[column].key
|
|
|
|
self._configure_property(
|
|
column_key, column, init=False, setparent=True
|
|
)
|
|
|
|
def _configure_polymorphic_setter(self, init=False):
|
|
"""Configure an attribute on the mapper representing the
|
|
'polymorphic_on' column, if applicable, and not
|
|
already generated by _configure_properties (which is typical).
|
|
|
|
Also create a setter function which will assign this
|
|
attribute to the value of the 'polymorphic_identity'
|
|
upon instance construction, also if applicable. This
|
|
routine will run when an instance is created.
|
|
|
|
"""
|
|
setter = False
|
|
|
|
if self.polymorphic_on is not None:
|
|
setter = True
|
|
|
|
if isinstance(self.polymorphic_on, util.string_types):
|
|
# polymorphic_on specified as a string - link
|
|
# it to mapped ColumnProperty
|
|
try:
|
|
self.polymorphic_on = self._props[self.polymorphic_on]
|
|
except KeyError as err:
|
|
util.raise_(
|
|
sa_exc.ArgumentError(
|
|
"Can't determine polymorphic_on "
|
|
"value '%s' - no attribute is "
|
|
"mapped to this name." % self.polymorphic_on
|
|
),
|
|
replace_context=err,
|
|
)
|
|
|
|
if self.polymorphic_on in self._columntoproperty:
|
|
# polymorphic_on is a column that is already mapped
|
|
# to a ColumnProperty
|
|
prop = self._columntoproperty[self.polymorphic_on]
|
|
elif isinstance(self.polymorphic_on, MapperProperty):
|
|
# polymorphic_on is directly a MapperProperty,
|
|
# ensure it's a ColumnProperty
|
|
if not isinstance(
|
|
self.polymorphic_on, properties.ColumnProperty
|
|
):
|
|
raise sa_exc.ArgumentError(
|
|
"Only direct column-mapped "
|
|
"property or SQL expression "
|
|
"can be passed for polymorphic_on"
|
|
)
|
|
prop = self.polymorphic_on
|
|
else:
|
|
# polymorphic_on is a Column or SQL expression and
|
|
# doesn't appear to be mapped. this means it can be 1.
|
|
# only present in the with_polymorphic selectable or
|
|
# 2. a totally standalone SQL expression which we'd
|
|
# hope is compatible with this mapper's persist_selectable
|
|
col = self.persist_selectable.corresponding_column(
|
|
self.polymorphic_on
|
|
)
|
|
if col is None:
|
|
# polymorphic_on doesn't derive from any
|
|
# column/expression isn't present in the mapped
|
|
# table. we will make a "hidden" ColumnProperty
|
|
# for it. Just check that if it's directly a
|
|
# schema.Column and we have with_polymorphic, it's
|
|
# likely a user error if the schema.Column isn't
|
|
# represented somehow in either persist_selectable or
|
|
# with_polymorphic. Otherwise as of 0.7.4 we
|
|
# just go with it and assume the user wants it
|
|
# that way (i.e. a CASE statement)
|
|
setter = False
|
|
instrument = False
|
|
col = self.polymorphic_on
|
|
if isinstance(col, schema.Column) and (
|
|
self.with_polymorphic is None
|
|
or self.with_polymorphic[1].corresponding_column(col)
|
|
is None
|
|
):
|
|
raise sa_exc.InvalidRequestError(
|
|
"Could not map polymorphic_on column "
|
|
"'%s' to the mapped table - polymorphic "
|
|
"loads will not function properly"
|
|
% col.description
|
|
)
|
|
else:
|
|
# column/expression that polymorphic_on derives from
|
|
# is present in our mapped table
|
|
# and is probably mapped, but polymorphic_on itself
|
|
# is not. This happens when
|
|
# the polymorphic_on is only directly present in the
|
|
# with_polymorphic selectable, as when use
|
|
# polymorphic_union.
|
|
# we'll make a separate ColumnProperty for it.
|
|
instrument = True
|
|
key = getattr(col, "key", None)
|
|
if key:
|
|
if self._should_exclude(col.key, col.key, False, col):
|
|
raise sa_exc.InvalidRequestError(
|
|
"Cannot exclude or override the "
|
|
"discriminator column %r" % col.key
|
|
)
|
|
else:
|
|
self.polymorphic_on = col = col.label("_sa_polymorphic_on")
|
|
key = col.key
|
|
|
|
prop = properties.ColumnProperty(col, _instrument=instrument)
|
|
self._configure_property(key, prop, init=init, setparent=True)
|
|
|
|
# the actual polymorphic_on should be the first public-facing
|
|
# column in the property
|
|
self.polymorphic_on = prop.columns[0]
|
|
polymorphic_key = prop.key
|
|
|
|
else:
|
|
# no polymorphic_on was set.
|
|
# check inheriting mappers for one.
|
|
for mapper in self.iterate_to_root():
|
|
# determine if polymorphic_on of the parent
|
|
# should be propagated here. If the col
|
|
# is present in our mapped table, or if our mapped
|
|
# table is the same as the parent (i.e. single table
|
|
# inheritance), we can use it
|
|
if mapper.polymorphic_on is not None:
|
|
if self.persist_selectable is mapper.persist_selectable:
|
|
self.polymorphic_on = mapper.polymorphic_on
|
|
else:
|
|
self.polymorphic_on = (
|
|
self.persist_selectable
|
|
).corresponding_column(mapper.polymorphic_on)
|
|
# we can use the parent mapper's _set_polymorphic_identity
|
|
# directly; it ensures the polymorphic_identity of the
|
|
# instance's mapper is used so is portable to subclasses.
|
|
if self.polymorphic_on is not None:
|
|
self._set_polymorphic_identity = (
|
|
mapper._set_polymorphic_identity
|
|
)
|
|
self._validate_polymorphic_identity = (
|
|
mapper._validate_polymorphic_identity
|
|
)
|
|
else:
|
|
self._set_polymorphic_identity = None
|
|
return
|
|
|
|
if setter:
|
|
|
|
def _set_polymorphic_identity(state):
|
|
dict_ = state.dict
|
|
state.get_impl(polymorphic_key).set(
|
|
state,
|
|
dict_,
|
|
state.manager.mapper.polymorphic_identity,
|
|
None,
|
|
)
|
|
|
|
def _validate_polymorphic_identity(mapper, state, dict_):
|
|
if (
|
|
polymorphic_key in dict_
|
|
and dict_[polymorphic_key]
|
|
not in mapper._acceptable_polymorphic_identities
|
|
):
|
|
util.warn_limited(
|
|
"Flushing object %s with "
|
|
"incompatible polymorphic identity %r; the "
|
|
"object may not refresh and/or load correctly",
|
|
(state_str(state), dict_[polymorphic_key]),
|
|
)
|
|
|
|
self._set_polymorphic_identity = _set_polymorphic_identity
|
|
self._validate_polymorphic_identity = (
|
|
_validate_polymorphic_identity
|
|
)
|
|
else:
|
|
self._set_polymorphic_identity = None
|
|
|
|
_validate_polymorphic_identity = None
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _version_id_prop(self):
|
|
if self.version_id_col is not None:
|
|
return self._columntoproperty[self.version_id_col]
|
|
else:
|
|
return None
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _acceptable_polymorphic_identities(self):
|
|
identities = set()
|
|
|
|
stack = deque([self])
|
|
while stack:
|
|
item = stack.popleft()
|
|
if item.persist_selectable is self.persist_selectable:
|
|
identities.add(item.polymorphic_identity)
|
|
stack.extend(item._inheriting_mappers)
|
|
|
|
return identities
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _prop_set(self):
|
|
return frozenset(self._props.values())
|
|
|
|
@util.preload_module("sqlalchemy.orm.descriptor_props")
|
|
def _adapt_inherited_property(self, key, prop, init):
|
|
descriptor_props = util.preloaded.orm_descriptor_props
|
|
|
|
if not self.concrete:
|
|
self._configure_property(key, prop, init=False, setparent=False)
|
|
elif key not in self._props:
|
|
# determine if the class implements this attribute; if not,
|
|
# or if it is implemented by the attribute that is handling the
|
|
# given superclass-mapped property, then we need to report that we
|
|
# can't use this at the instance level since we are a concrete
|
|
# mapper and we don't map this. don't trip user-defined
|
|
# descriptors that might have side effects when invoked.
|
|
implementing_attribute = self.class_manager._get_class_attr_mro(
|
|
key, prop
|
|
)
|
|
if implementing_attribute is prop or (
|
|
isinstance(
|
|
implementing_attribute, attributes.InstrumentedAttribute
|
|
)
|
|
and implementing_attribute._parententity is prop.parent
|
|
):
|
|
self._configure_property(
|
|
key,
|
|
descriptor_props.ConcreteInheritedProperty(),
|
|
init=init,
|
|
setparent=True,
|
|
)
|
|
|
|
@util.preload_module("sqlalchemy.orm.descriptor_props")
|
|
def _configure_property(self, key, prop, init=True, setparent=True):
|
|
descriptor_props = util.preloaded.orm_descriptor_props
|
|
self._log("_configure_property(%s, %s)", key, prop.__class__.__name__)
|
|
|
|
if not isinstance(prop, MapperProperty):
|
|
prop = self._property_from_column(key, prop)
|
|
|
|
if isinstance(prop, properties.ColumnProperty):
|
|
col = self.persist_selectable.corresponding_column(prop.columns[0])
|
|
|
|
# if the column is not present in the mapped table,
|
|
# test if a column has been added after the fact to the
|
|
# parent table (or their parent, etc.) [ticket:1570]
|
|
if col is None and self.inherits:
|
|
path = [self]
|
|
for m in self.inherits.iterate_to_root():
|
|
col = m.local_table.corresponding_column(prop.columns[0])
|
|
if col is not None:
|
|
for m2 in path:
|
|
m2.persist_selectable._refresh_for_new_column(col)
|
|
col = self.persist_selectable.corresponding_column(
|
|
prop.columns[0]
|
|
)
|
|
break
|
|
path.append(m)
|
|
|
|
# subquery expression, column not present in the mapped
|
|
# selectable.
|
|
if col is None:
|
|
col = prop.columns[0]
|
|
|
|
# column is coming in after _readonly_props was
|
|
# initialized; check for 'readonly'
|
|
if hasattr(self, "_readonly_props") and (
|
|
not hasattr(col, "table")
|
|
or col.table not in self._cols_by_table
|
|
):
|
|
self._readonly_props.add(prop)
|
|
|
|
else:
|
|
# if column is coming in after _cols_by_table was
|
|
# initialized, ensure the col is in the right set
|
|
if (
|
|
hasattr(self, "_cols_by_table")
|
|
and col.table in self._cols_by_table
|
|
and col not in self._cols_by_table[col.table]
|
|
):
|
|
self._cols_by_table[col.table].add(col)
|
|
|
|
# if this properties.ColumnProperty represents the "polymorphic
|
|
# discriminator" column, mark it. We'll need this when rendering
|
|
# columns in SELECT statements.
|
|
if not hasattr(prop, "_is_polymorphic_discriminator"):
|
|
prop._is_polymorphic_discriminator = (
|
|
col is self.polymorphic_on
|
|
or prop.columns[0] is self.polymorphic_on
|
|
)
|
|
|
|
if isinstance(col, expression.Label):
|
|
# new in 1.4, get column property against expressions
|
|
# to be addressable in subqueries
|
|
col.key = col._tq_key_label = key
|
|
|
|
self.columns.add(col, key)
|
|
for col in prop.columns + prop._orig_columns:
|
|
for col in col.proxy_set:
|
|
self._columntoproperty[col] = prop
|
|
|
|
prop.key = key
|
|
|
|
if setparent:
|
|
prop.set_parent(self, init)
|
|
|
|
if key in self._props and getattr(
|
|
self._props[key], "_mapped_by_synonym", False
|
|
):
|
|
syn = self._props[key]._mapped_by_synonym
|
|
raise sa_exc.ArgumentError(
|
|
"Can't call map_column=True for synonym %r=%r, "
|
|
"a ColumnProperty already exists keyed to the name "
|
|
"%r for column %r" % (syn, key, key, syn)
|
|
)
|
|
|
|
if (
|
|
key in self._props
|
|
and not isinstance(prop, properties.ColumnProperty)
|
|
and not isinstance(
|
|
self._props[key],
|
|
(
|
|
properties.ColumnProperty,
|
|
descriptor_props.ConcreteInheritedProperty,
|
|
),
|
|
)
|
|
):
|
|
util.warn(
|
|
"Property %s on %s being replaced with new "
|
|
"property %s; the old property will be discarded"
|
|
% (self._props[key], self, prop)
|
|
)
|
|
oldprop = self._props[key]
|
|
self._path_registry.pop(oldprop, None)
|
|
|
|
self._props[key] = prop
|
|
|
|
if not self.non_primary:
|
|
prop.instrument_class(self)
|
|
|
|
for mapper in self._inheriting_mappers:
|
|
mapper._adapt_inherited_property(key, prop, init)
|
|
|
|
if init:
|
|
prop.init()
|
|
prop.post_instrument_class(self)
|
|
|
|
if self.configured:
|
|
self._expire_memoizations()
|
|
|
|
@util.preload_module("sqlalchemy.orm.descriptor_props")
|
|
def _property_from_column(self, key, prop):
|
|
"""generate/update a :class:`.ColumnProperty` given a
|
|
:class:`_schema.Column` object."""
|
|
descriptor_props = util.preloaded.orm_descriptor_props
|
|
# we were passed a Column or a list of Columns;
|
|
# generate a properties.ColumnProperty
|
|
columns = util.to_list(prop)
|
|
column = columns[0]
|
|
assert isinstance(column, expression.ColumnElement)
|
|
|
|
prop = self._props.get(key, None)
|
|
|
|
if isinstance(prop, properties.ColumnProperty):
|
|
if (
|
|
(
|
|
not self._inherits_equated_pairs
|
|
or (prop.columns[0], column)
|
|
not in self._inherits_equated_pairs
|
|
)
|
|
and not prop.columns[0].shares_lineage(column)
|
|
and prop.columns[0] is not self.version_id_col
|
|
and column is not self.version_id_col
|
|
):
|
|
warn_only = prop.parent is not self
|
|
msg = (
|
|
"Implicitly combining column %s with column "
|
|
"%s under attribute '%s'. Please configure one "
|
|
"or more attributes for these same-named columns "
|
|
"explicitly." % (prop.columns[-1], column, key)
|
|
)
|
|
if warn_only:
|
|
util.warn(msg)
|
|
else:
|
|
raise sa_exc.InvalidRequestError(msg)
|
|
|
|
# existing properties.ColumnProperty from an inheriting
|
|
# mapper. make a copy and append our column to it
|
|
prop = prop.copy()
|
|
prop.columns.insert(0, column)
|
|
self._log(
|
|
"inserting column to existing list "
|
|
"in properties.ColumnProperty %s" % (key)
|
|
)
|
|
return prop
|
|
elif prop is None or isinstance(
|
|
prop, descriptor_props.ConcreteInheritedProperty
|
|
):
|
|
mapped_column = []
|
|
for c in columns:
|
|
mc = self.persist_selectable.corresponding_column(c)
|
|
if mc is None:
|
|
mc = self.local_table.corresponding_column(c)
|
|
if mc is not None:
|
|
# if the column is in the local table but not the
|
|
# mapped table, this corresponds to adding a
|
|
# column after the fact to the local table.
|
|
# [ticket:1523]
|
|
self.persist_selectable._refresh_for_new_column(mc)
|
|
mc = self.persist_selectable.corresponding_column(c)
|
|
if mc is None:
|
|
raise sa_exc.ArgumentError(
|
|
"When configuring property '%s' on %s, "
|
|
"column '%s' is not represented in the mapper's "
|
|
"table. Use the `column_property()` function to "
|
|
"force this column to be mapped as a read-only "
|
|
"attribute." % (key, self, c)
|
|
)
|
|
mapped_column.append(mc)
|
|
return properties.ColumnProperty(*mapped_column)
|
|
else:
|
|
raise sa_exc.ArgumentError(
|
|
"WARNING: when configuring property '%s' on %s, "
|
|
"column '%s' conflicts with property '%r'. "
|
|
"To resolve this, map the column to the class under a "
|
|
"different name in the 'properties' dictionary. Or, "
|
|
"to remove all awareness of the column entirely "
|
|
"(including its availability as a foreign key), "
|
|
"use the 'include_properties' or 'exclude_properties' "
|
|
"mapper arguments to control specifically which table "
|
|
"columns get mapped." % (key, self, column.key, prop)
|
|
)
|
|
|
|
def _check_configure(self):
|
|
if self.registry._new_mappers:
|
|
_configure_registries({self.registry}, cascade=True)
|
|
|
|
def _post_configure_properties(self):
|
|
"""Call the ``init()`` method on all ``MapperProperties``
|
|
attached to this mapper.
|
|
|
|
This is a deferred configuration step which is intended
|
|
to execute once all mappers have been constructed.
|
|
|
|
"""
|
|
|
|
self._log("_post_configure_properties() started")
|
|
l = [(key, prop) for key, prop in self._props.items()]
|
|
for key, prop in l:
|
|
self._log("initialize prop %s", key)
|
|
|
|
if prop.parent is self and not prop._configure_started:
|
|
prop.init()
|
|
|
|
if prop._configure_finished:
|
|
prop.post_instrument_class(self)
|
|
|
|
self._log("_post_configure_properties() complete")
|
|
self.configured = True
|
|
|
|
def add_properties(self, dict_of_properties):
|
|
"""Add the given dictionary of properties to this mapper,
|
|
using `add_property`.
|
|
|
|
"""
|
|
for key, value in dict_of_properties.items():
|
|
self.add_property(key, value)
|
|
|
|
def add_property(self, key, prop):
|
|
"""Add an individual MapperProperty to this mapper.
|
|
|
|
If the mapper has not been configured yet, just adds the
|
|
property to the initial properties dictionary sent to the
|
|
constructor. If this Mapper has already been configured, then
|
|
the given MapperProperty is configured immediately.
|
|
|
|
"""
|
|
self._init_properties[key] = prop
|
|
self._configure_property(key, prop, init=self.configured)
|
|
|
|
def _expire_memoizations(self):
|
|
for mapper in self.iterate_to_root():
|
|
mapper._reset_memoizations()
|
|
|
|
@property
|
|
def _log_desc(self):
|
|
return (
|
|
"("
|
|
+ self.class_.__name__
|
|
+ "|"
|
|
+ (
|
|
self.local_table is not None
|
|
and self.local_table.description
|
|
or str(self.local_table)
|
|
)
|
|
+ (self.non_primary and "|non-primary" or "")
|
|
+ ")"
|
|
)
|
|
|
|
def _log(self, msg, *args):
|
|
self.logger.info("%s " + msg, *((self._log_desc,) + args))
|
|
|
|
def _log_debug(self, msg, *args):
|
|
self.logger.debug("%s " + msg, *((self._log_desc,) + args))
|
|
|
|
def __repr__(self):
|
|
return "<Mapper at 0x%x; %s>" % (id(self), self.class_.__name__)
|
|
|
|
def __str__(self):
|
|
return "mapped class %s%s->%s" % (
|
|
self.class_.__name__,
|
|
self.non_primary and " (non-primary)" or "",
|
|
self.local_table.description
|
|
if self.local_table is not None
|
|
else self.persist_selectable.description,
|
|
)
|
|
|
|
def _is_orphan(self, state):
|
|
orphan_possible = False
|
|
for mapper in self.iterate_to_root():
|
|
for (key, cls) in mapper._delete_orphans:
|
|
orphan_possible = True
|
|
|
|
has_parent = attributes.manager_of_class(cls).has_parent(
|
|
state, key, optimistic=state.has_identity
|
|
)
|
|
|
|
if self.legacy_is_orphan and has_parent:
|
|
return False
|
|
elif not self.legacy_is_orphan and not has_parent:
|
|
return True
|
|
|
|
if self.legacy_is_orphan:
|
|
return orphan_possible
|
|
else:
|
|
return False
|
|
|
|
def has_property(self, key):
|
|
return key in self._props
|
|
|
|
def get_property(self, key, _configure_mappers=True):
|
|
"""return a MapperProperty associated with the given key."""
|
|
|
|
if _configure_mappers:
|
|
self._check_configure()
|
|
|
|
try:
|
|
return self._props[key]
|
|
except KeyError as err:
|
|
util.raise_(
|
|
sa_exc.InvalidRequestError(
|
|
"Mapper '%s' has no property '%s'" % (self, key)
|
|
),
|
|
replace_context=err,
|
|
)
|
|
|
|
def get_property_by_column(self, column):
|
|
"""Given a :class:`_schema.Column` object, return the
|
|
:class:`.MapperProperty` which maps this column."""
|
|
|
|
return self._columntoproperty[column]
|
|
|
|
@property
|
|
def iterate_properties(self):
|
|
"""return an iterator of all MapperProperty objects."""
|
|
|
|
self._check_configure()
|
|
return iter(self._props.values())
|
|
|
|
def _mappers_from_spec(self, spec, selectable):
|
|
"""given a with_polymorphic() argument, return the set of mappers it
|
|
represents.
|
|
|
|
Trims the list of mappers to just those represented within the given
|
|
selectable, if present. This helps some more legacy-ish mappings.
|
|
|
|
"""
|
|
if spec == "*":
|
|
mappers = list(self.self_and_descendants)
|
|
elif spec:
|
|
mappers = set()
|
|
for m in util.to_list(spec):
|
|
m = _class_to_mapper(m)
|
|
if not m.isa(self):
|
|
raise sa_exc.InvalidRequestError(
|
|
"%r does not inherit from %r" % (m, self)
|
|
)
|
|
|
|
if selectable is None:
|
|
mappers.update(m.iterate_to_root())
|
|
else:
|
|
mappers.add(m)
|
|
mappers = [m for m in self.self_and_descendants if m in mappers]
|
|
else:
|
|
mappers = []
|
|
|
|
if selectable is not None:
|
|
tables = set(
|
|
sql_util.find_tables(selectable, include_aliases=True)
|
|
)
|
|
mappers = [m for m in mappers if m.local_table in tables]
|
|
return mappers
|
|
|
|
def _selectable_from_mappers(self, mappers, innerjoin):
|
|
"""given a list of mappers (assumed to be within this mapper's
|
|
inheritance hierarchy), construct an outerjoin amongst those mapper's
|
|
mapped tables.
|
|
|
|
"""
|
|
from_obj = self.persist_selectable
|
|
for m in mappers:
|
|
if m is self:
|
|
continue
|
|
if m.concrete:
|
|
raise sa_exc.InvalidRequestError(
|
|
"'with_polymorphic()' requires 'selectable' argument "
|
|
"when concrete-inheriting mappers are used."
|
|
)
|
|
elif not m.single:
|
|
if innerjoin:
|
|
from_obj = from_obj.join(
|
|
m.local_table, m.inherit_condition
|
|
)
|
|
else:
|
|
from_obj = from_obj.outerjoin(
|
|
m.local_table, m.inherit_condition
|
|
)
|
|
|
|
return from_obj
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _single_table_criterion(self):
|
|
if self.single and self.inherits and self.polymorphic_on is not None:
|
|
return self.polymorphic_on._annotate({"parentmapper": self}).in_(
|
|
m.polymorphic_identity for m in self.self_and_descendants
|
|
)
|
|
else:
|
|
return None
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _with_polymorphic_mappers(self):
|
|
self._check_configure()
|
|
|
|
if not self.with_polymorphic:
|
|
return []
|
|
return self._mappers_from_spec(*self.with_polymorphic)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _post_inspect(self):
|
|
"""This hook is invoked by attribute inspection.
|
|
|
|
E.g. when Query calls:
|
|
|
|
coercions.expect(roles.ColumnsClauseRole, ent, keep_inspect=True)
|
|
|
|
This allows the inspection process run a configure mappers hook.
|
|
|
|
"""
|
|
self._check_configure()
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _with_polymorphic_selectable(self):
|
|
if not self.with_polymorphic:
|
|
return self.persist_selectable
|
|
|
|
spec, selectable = self.with_polymorphic
|
|
if selectable is not None:
|
|
return selectable
|
|
else:
|
|
return self._selectable_from_mappers(
|
|
self._mappers_from_spec(spec, selectable), False
|
|
)
|
|
|
|
with_polymorphic_mappers = _with_polymorphic_mappers
|
|
"""The list of :class:`_orm.Mapper` objects included in the
|
|
default "polymorphic" query.
|
|
|
|
"""
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _insert_cols_evaluating_none(self):
|
|
return dict(
|
|
(
|
|
table,
|
|
frozenset(
|
|
col for col in columns if col.type.should_evaluate_none
|
|
),
|
|
)
|
|
for table, columns in self._cols_by_table.items()
|
|
)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _insert_cols_as_none(self):
|
|
return dict(
|
|
(
|
|
table,
|
|
frozenset(
|
|
col.key
|
|
for col in columns
|
|
if not col.primary_key
|
|
and not col.server_default
|
|
and not col.default
|
|
and not col.type.should_evaluate_none
|
|
),
|
|
)
|
|
for table, columns in self._cols_by_table.items()
|
|
)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _propkey_to_col(self):
|
|
return dict(
|
|
(
|
|
table,
|
|
dict(
|
|
(self._columntoproperty[col].key, col) for col in columns
|
|
),
|
|
)
|
|
for table, columns in self._cols_by_table.items()
|
|
)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _pk_keys_by_table(self):
|
|
return dict(
|
|
(table, frozenset([col.key for col in pks]))
|
|
for table, pks in self._pks_by_table.items()
|
|
)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _pk_attr_keys_by_table(self):
|
|
return dict(
|
|
(
|
|
table,
|
|
frozenset([self._columntoproperty[col].key for col in pks]),
|
|
)
|
|
for table, pks in self._pks_by_table.items()
|
|
)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _server_default_cols(self):
|
|
return dict(
|
|
(
|
|
table,
|
|
frozenset(
|
|
[
|
|
col.key
|
|
for col in columns
|
|
if col.server_default is not None
|
|
]
|
|
),
|
|
)
|
|
for table, columns in self._cols_by_table.items()
|
|
)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _server_default_plus_onupdate_propkeys(self):
|
|
result = set()
|
|
|
|
for table, columns in self._cols_by_table.items():
|
|
for col in columns:
|
|
if (
|
|
col.server_default is not None
|
|
or col.server_onupdate is not None
|
|
) and col in self._columntoproperty:
|
|
result.add(self._columntoproperty[col].key)
|
|
|
|
return result
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _server_onupdate_default_cols(self):
|
|
return dict(
|
|
(
|
|
table,
|
|
frozenset(
|
|
[
|
|
col.key
|
|
for col in columns
|
|
if col.server_onupdate is not None
|
|
]
|
|
),
|
|
)
|
|
for table, columns in self._cols_by_table.items()
|
|
)
|
|
|
|
@HasMemoized.memoized_instancemethod
|
|
def __clause_element__(self):
|
|
|
|
annotations = {
|
|
"entity_namespace": self,
|
|
"parententity": self,
|
|
"parentmapper": self,
|
|
}
|
|
if self.persist_selectable is not self.local_table:
|
|
# joined table inheritance, with polymorphic selectable,
|
|
# etc.
|
|
annotations["dml_table"] = self.local_table._annotate(
|
|
{
|
|
"entity_namespace": self,
|
|
"parententity": self,
|
|
"parentmapper": self,
|
|
}
|
|
)._set_propagate_attrs(
|
|
{"compile_state_plugin": "orm", "plugin_subject": self}
|
|
)
|
|
|
|
return self.selectable._annotate(annotations)._set_propagate_attrs(
|
|
{"compile_state_plugin": "orm", "plugin_subject": self}
|
|
)
|
|
|
|
@util.memoized_property
|
|
def select_identity_token(self):
|
|
return (
|
|
expression.null()
|
|
._annotate(
|
|
{
|
|
"entity_namespace": self,
|
|
"parententity": self,
|
|
"parentmapper": self,
|
|
"identity_token": True,
|
|
}
|
|
)
|
|
._set_propagate_attrs(
|
|
{"compile_state_plugin": "orm", "plugin_subject": self}
|
|
)
|
|
)
|
|
|
|
@property
|
|
def selectable(self):
|
|
"""The :class:`_schema.FromClause` construct this
|
|
:class:`_orm.Mapper` selects from by default.
|
|
|
|
Normally, this is equivalent to :attr:`.persist_selectable`, unless
|
|
the ``with_polymorphic`` feature is in use, in which case the
|
|
full "polymorphic" selectable is returned.
|
|
|
|
"""
|
|
return self._with_polymorphic_selectable
|
|
|
|
def _with_polymorphic_args(
|
|
self, spec=None, selectable=False, innerjoin=False
|
|
):
|
|
if selectable not in (None, False):
|
|
selectable = coercions.expect(
|
|
roles.StrictFromClauseRole, selectable, allow_select=True
|
|
)
|
|
|
|
if self.with_polymorphic:
|
|
if not spec:
|
|
spec = self.with_polymorphic[0]
|
|
if selectable is False:
|
|
selectable = self.with_polymorphic[1]
|
|
elif selectable is False:
|
|
selectable = None
|
|
mappers = self._mappers_from_spec(spec, selectable)
|
|
if selectable is not None:
|
|
return mappers, selectable
|
|
else:
|
|
return mappers, self._selectable_from_mappers(mappers, innerjoin)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _polymorphic_properties(self):
|
|
return list(
|
|
self._iterate_polymorphic_properties(
|
|
self._with_polymorphic_mappers
|
|
)
|
|
)
|
|
|
|
@property
|
|
def _all_column_expressions(self):
|
|
poly_properties = self._polymorphic_properties
|
|
adapter = self._polymorphic_adapter
|
|
|
|
return [
|
|
adapter.columns[prop.columns[0]] if adapter else prop.columns[0]
|
|
for prop in poly_properties
|
|
if isinstance(prop, properties.ColumnProperty)
|
|
and prop._renders_in_subqueries
|
|
]
|
|
|
|
def _columns_plus_keys(self, polymorphic_mappers=()):
|
|
if polymorphic_mappers:
|
|
poly_properties = self._iterate_polymorphic_properties(
|
|
polymorphic_mappers
|
|
)
|
|
else:
|
|
poly_properties = self._polymorphic_properties
|
|
|
|
return [
|
|
(prop.key, prop.columns[0])
|
|
for prop in poly_properties
|
|
if isinstance(prop, properties.ColumnProperty)
|
|
]
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _polymorphic_adapter(self):
|
|
if self.with_polymorphic:
|
|
return sql_util.ColumnAdapter(
|
|
self.selectable, equivalents=self._equivalent_columns
|
|
)
|
|
else:
|
|
return None
|
|
|
|
def _iterate_polymorphic_properties(self, mappers=None):
|
|
"""Return an iterator of MapperProperty objects which will render into
|
|
a SELECT."""
|
|
if mappers is None:
|
|
mappers = self._with_polymorphic_mappers
|
|
|
|
if not mappers:
|
|
for c in self.iterate_properties:
|
|
yield c
|
|
else:
|
|
# in the polymorphic case, filter out discriminator columns
|
|
# from other mappers, as these are sometimes dependent on that
|
|
# mapper's polymorphic selectable (which we don't want rendered)
|
|
for c in util.unique_list(
|
|
chain(
|
|
*[
|
|
list(mapper.iterate_properties)
|
|
for mapper in [self] + mappers
|
|
]
|
|
)
|
|
):
|
|
if getattr(c, "_is_polymorphic_discriminator", False) and (
|
|
self.polymorphic_on is None
|
|
or c.columns[0] is not self.polymorphic_on
|
|
):
|
|
continue
|
|
yield c
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def attrs(self):
|
|
"""A namespace of all :class:`.MapperProperty` objects
|
|
associated this mapper.
|
|
|
|
This is an object that provides each property based on
|
|
its key name. For instance, the mapper for a
|
|
``User`` class which has ``User.name`` attribute would
|
|
provide ``mapper.attrs.name``, which would be the
|
|
:class:`.ColumnProperty` representing the ``name``
|
|
column. The namespace object can also be iterated,
|
|
which would yield each :class:`.MapperProperty`.
|
|
|
|
:class:`_orm.Mapper` has several pre-filtered views
|
|
of this attribute which limit the types of properties
|
|
returned, including :attr:`.synonyms`, :attr:`.column_attrs`,
|
|
:attr:`.relationships`, and :attr:`.composites`.
|
|
|
|
.. warning::
|
|
|
|
The :attr:`_orm.Mapper.attrs` accessor namespace is an
|
|
instance of :class:`.OrderedProperties`. This is
|
|
a dictionary-like object which includes a small number of
|
|
named methods such as :meth:`.OrderedProperties.items`
|
|
and :meth:`.OrderedProperties.values`. When
|
|
accessing attributes dynamically, favor using the dict-access
|
|
scheme, e.g. ``mapper.attrs[somename]`` over
|
|
``getattr(mapper.attrs, somename)`` to avoid name collisions.
|
|
|
|
.. seealso::
|
|
|
|
:attr:`_orm.Mapper.all_orm_descriptors`
|
|
|
|
"""
|
|
|
|
self._check_configure()
|
|
return util.ImmutableProperties(self._props)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def all_orm_descriptors(self):
|
|
"""A namespace of all :class:`.InspectionAttr` attributes associated
|
|
with the mapped class.
|
|
|
|
These attributes are in all cases Python :term:`descriptors`
|
|
associated with the mapped class or its superclasses.
|
|
|
|
This namespace includes attributes that are mapped to the class
|
|
as well as attributes declared by extension modules.
|
|
It includes any Python descriptor type that inherits from
|
|
:class:`.InspectionAttr`. This includes
|
|
:class:`.QueryableAttribute`, as well as extension types such as
|
|
:class:`.hybrid_property`, :class:`.hybrid_method` and
|
|
:class:`.AssociationProxy`.
|
|
|
|
To distinguish between mapped attributes and extension attributes,
|
|
the attribute :attr:`.InspectionAttr.extension_type` will refer
|
|
to a constant that distinguishes between different extension types.
|
|
|
|
The sorting of the attributes is based on the following rules:
|
|
|
|
1. Iterate through the class and its superclasses in order from
|
|
subclass to superclass (i.e. iterate through ``cls.__mro__``)
|
|
|
|
2. For each class, yield the attributes in the order in which they
|
|
appear in ``__dict__``, with the exception of those in step
|
|
3 below. In Python 3.6 and above this ordering will be the
|
|
same as that of the class' construction, with the exception
|
|
of attributes that were added after the fact by the application
|
|
or the mapper.
|
|
|
|
3. If a certain attribute key is also in the superclass ``__dict__``,
|
|
then it's included in the iteration for that class, and not the
|
|
class in which it first appeared.
|
|
|
|
The above process produces an ordering that is deterministic in terms
|
|
of the order in which attributes were assigned to the class.
|
|
|
|
.. versionchanged:: 1.3.19 ensured deterministic ordering for
|
|
:meth:`_orm.Mapper.all_orm_descriptors`.
|
|
|
|
When dealing with a :class:`.QueryableAttribute`, the
|
|
:attr:`.QueryableAttribute.property` attribute refers to the
|
|
:class:`.MapperProperty` property, which is what you get when
|
|
referring to the collection of mapped properties via
|
|
:attr:`_orm.Mapper.attrs`.
|
|
|
|
.. warning::
|
|
|
|
The :attr:`_orm.Mapper.all_orm_descriptors`
|
|
accessor namespace is an
|
|
instance of :class:`.OrderedProperties`. This is
|
|
a dictionary-like object which includes a small number of
|
|
named methods such as :meth:`.OrderedProperties.items`
|
|
and :meth:`.OrderedProperties.values`. When
|
|
accessing attributes dynamically, favor using the dict-access
|
|
scheme, e.g. ``mapper.all_orm_descriptors[somename]`` over
|
|
``getattr(mapper.all_orm_descriptors, somename)`` to avoid name
|
|
collisions.
|
|
|
|
.. seealso::
|
|
|
|
:attr:`_orm.Mapper.attrs`
|
|
|
|
"""
|
|
return util.ImmutableProperties(
|
|
dict(self.class_manager._all_sqla_attributes())
|
|
)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
@util.preload_module("sqlalchemy.orm.descriptor_props")
|
|
def synonyms(self):
|
|
"""Return a namespace of all :class:`.SynonymProperty`
|
|
properties maintained by this :class:`_orm.Mapper`.
|
|
|
|
.. seealso::
|
|
|
|
:attr:`_orm.Mapper.attrs` - namespace of all
|
|
:class:`.MapperProperty`
|
|
objects.
|
|
|
|
"""
|
|
descriptor_props = util.preloaded.orm_descriptor_props
|
|
|
|
return self._filter_properties(descriptor_props.SynonymProperty)
|
|
|
|
@property
|
|
def entity_namespace(self):
|
|
return self.class_
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def column_attrs(self):
|
|
"""Return a namespace of all :class:`.ColumnProperty`
|
|
properties maintained by this :class:`_orm.Mapper`.
|
|
|
|
.. seealso::
|
|
|
|
:attr:`_orm.Mapper.attrs` - namespace of all
|
|
:class:`.MapperProperty`
|
|
objects.
|
|
|
|
"""
|
|
return self._filter_properties(properties.ColumnProperty)
|
|
|
|
@util.preload_module("sqlalchemy.orm.relationships")
|
|
@HasMemoized.memoized_attribute
|
|
def relationships(self):
|
|
"""A namespace of all :class:`.RelationshipProperty` properties
|
|
maintained by this :class:`_orm.Mapper`.
|
|
|
|
.. warning::
|
|
|
|
the :attr:`_orm.Mapper.relationships` accessor namespace is an
|
|
instance of :class:`.OrderedProperties`. This is
|
|
a dictionary-like object which includes a small number of
|
|
named methods such as :meth:`.OrderedProperties.items`
|
|
and :meth:`.OrderedProperties.values`. When
|
|
accessing attributes dynamically, favor using the dict-access
|
|
scheme, e.g. ``mapper.relationships[somename]`` over
|
|
``getattr(mapper.relationships, somename)`` to avoid name
|
|
collisions.
|
|
|
|
.. seealso::
|
|
|
|
:attr:`_orm.Mapper.attrs` - namespace of all
|
|
:class:`.MapperProperty`
|
|
objects.
|
|
|
|
"""
|
|
return self._filter_properties(
|
|
util.preloaded.orm_relationships.RelationshipProperty
|
|
)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
@util.preload_module("sqlalchemy.orm.descriptor_props")
|
|
def composites(self):
|
|
"""Return a namespace of all :class:`.CompositeProperty`
|
|
properties maintained by this :class:`_orm.Mapper`.
|
|
|
|
.. seealso::
|
|
|
|
:attr:`_orm.Mapper.attrs` - namespace of all
|
|
:class:`.MapperProperty`
|
|
objects.
|
|
|
|
"""
|
|
return self._filter_properties(
|
|
util.preloaded.orm_descriptor_props.CompositeProperty
|
|
)
|
|
|
|
def _filter_properties(self, type_):
|
|
self._check_configure()
|
|
return util.ImmutableProperties(
|
|
util.OrderedDict(
|
|
(k, v) for k, v in self._props.items() if isinstance(v, type_)
|
|
)
|
|
)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _get_clause(self):
|
|
"""create a "get clause" based on the primary key. this is used
|
|
by query.get() and many-to-one lazyloads to load this item
|
|
by primary key.
|
|
|
|
"""
|
|
params = [
|
|
(
|
|
primary_key,
|
|
sql.bindparam("pk_%d" % idx, type_=primary_key.type),
|
|
)
|
|
for idx, primary_key in enumerate(self.primary_key, 1)
|
|
]
|
|
return (
|
|
sql.and_(*[k == v for (k, v) in params]),
|
|
util.column_dict(params),
|
|
)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _equivalent_columns(self):
|
|
"""Create a map of all equivalent columns, based on
|
|
the determination of column pairs that are equated to
|
|
one another based on inherit condition. This is designed
|
|
to work with the queries that util.polymorphic_union
|
|
comes up with, which often don't include the columns from
|
|
the base table directly (including the subclass table columns
|
|
only).
|
|
|
|
The resulting structure is a dictionary of columns mapped
|
|
to lists of equivalent columns, e.g.::
|
|
|
|
{
|
|
tablea.col1:
|
|
{tableb.col1, tablec.col1},
|
|
tablea.col2:
|
|
{tabled.col2}
|
|
}
|
|
|
|
"""
|
|
result = util.column_dict()
|
|
|
|
def visit_binary(binary):
|
|
if binary.operator == operators.eq:
|
|
if binary.left in result:
|
|
result[binary.left].add(binary.right)
|
|
else:
|
|
result[binary.left] = util.column_set((binary.right,))
|
|
if binary.right in result:
|
|
result[binary.right].add(binary.left)
|
|
else:
|
|
result[binary.right] = util.column_set((binary.left,))
|
|
|
|
for mapper in self.base_mapper.self_and_descendants:
|
|
if mapper.inherit_condition is not None:
|
|
visitors.traverse(
|
|
mapper.inherit_condition, {}, {"binary": visit_binary}
|
|
)
|
|
|
|
return result
|
|
|
|
def _is_userland_descriptor(self, assigned_name, obj):
|
|
if isinstance(
|
|
obj,
|
|
(
|
|
_MappedAttribute,
|
|
instrumentation.ClassManager,
|
|
expression.ColumnElement,
|
|
),
|
|
):
|
|
return False
|
|
else:
|
|
return assigned_name not in self._dataclass_fields
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _dataclass_fields(self):
|
|
return [f.name for f in util.dataclass_fields(self.class_)]
|
|
|
|
def _should_exclude(self, name, assigned_name, local, column):
|
|
"""determine whether a particular property should be implicitly
|
|
present on the class.
|
|
|
|
This occurs when properties are propagated from an inherited class, or
|
|
are applied from the columns present in the mapped table.
|
|
|
|
"""
|
|
|
|
# check for class-bound attributes and/or descriptors,
|
|
# either local or from an inherited class
|
|
# ignore dataclass field default values
|
|
if local:
|
|
if self.class_.__dict__.get(
|
|
assigned_name, None
|
|
) is not None and self._is_userland_descriptor(
|
|
assigned_name, self.class_.__dict__[assigned_name]
|
|
):
|
|
return True
|
|
else:
|
|
attr = self.class_manager._get_class_attr_mro(assigned_name, None)
|
|
if attr is not None and self._is_userland_descriptor(
|
|
assigned_name, attr
|
|
):
|
|
return True
|
|
|
|
if (
|
|
self.include_properties is not None
|
|
and name not in self.include_properties
|
|
and (column is None or column not in self.include_properties)
|
|
):
|
|
self._log("not including property %s" % (name))
|
|
return True
|
|
|
|
if self.exclude_properties is not None and (
|
|
name in self.exclude_properties
|
|
or (column is not None and column in self.exclude_properties)
|
|
):
|
|
self._log("excluding property %s" % (name))
|
|
return True
|
|
|
|
return False
|
|
|
|
def common_parent(self, other):
|
|
"""Return true if the given mapper shares a
|
|
common inherited parent as this mapper."""
|
|
|
|
return self.base_mapper is other.base_mapper
|
|
|
|
def is_sibling(self, other):
|
|
"""return true if the other mapper is an inheriting sibling to this
|
|
one. common parent but different branch
|
|
|
|
"""
|
|
return (
|
|
self.base_mapper is other.base_mapper
|
|
and not self.isa(other)
|
|
and not other.isa(self)
|
|
)
|
|
|
|
def _canload(self, state, allow_subtypes):
|
|
s = self.primary_mapper()
|
|
if self.polymorphic_on is not None or allow_subtypes:
|
|
return _state_mapper(state).isa(s)
|
|
else:
|
|
return _state_mapper(state) is s
|
|
|
|
def isa(self, other):
|
|
"""Return True if the this mapper inherits from the given mapper."""
|
|
|
|
m = self
|
|
while m and m is not other:
|
|
m = m.inherits
|
|
return bool(m)
|
|
|
|
def iterate_to_root(self):
|
|
m = self
|
|
while m:
|
|
yield m
|
|
m = m.inherits
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def self_and_descendants(self):
|
|
"""The collection including this mapper and all descendant mappers.
|
|
|
|
This includes not just the immediately inheriting mappers but
|
|
all their inheriting mappers as well.
|
|
|
|
"""
|
|
descendants = []
|
|
stack = deque([self])
|
|
while stack:
|
|
item = stack.popleft()
|
|
descendants.append(item)
|
|
stack.extend(item._inheriting_mappers)
|
|
return util.WeakSequence(descendants)
|
|
|
|
def polymorphic_iterator(self):
|
|
"""Iterate through the collection including this mapper and
|
|
all descendant mappers.
|
|
|
|
This includes not just the immediately inheriting mappers but
|
|
all their inheriting mappers as well.
|
|
|
|
To iterate through an entire hierarchy, use
|
|
``mapper.base_mapper.polymorphic_iterator()``.
|
|
|
|
"""
|
|
return iter(self.self_and_descendants)
|
|
|
|
def primary_mapper(self):
|
|
"""Return the primary mapper corresponding to this mapper's class key
|
|
(class)."""
|
|
|
|
return self.class_manager.mapper
|
|
|
|
@property
|
|
def primary_base_mapper(self):
|
|
return self.class_manager.mapper.base_mapper
|
|
|
|
def _result_has_identity_key(self, result, adapter=None):
|
|
pk_cols = self.primary_key
|
|
if adapter:
|
|
pk_cols = [adapter.columns[c] for c in pk_cols]
|
|
rk = result.keys()
|
|
for col in pk_cols:
|
|
if col not in rk:
|
|
return False
|
|
else:
|
|
return True
|
|
|
|
def identity_key_from_row(self, row, identity_token=None, adapter=None):
|
|
"""Return an identity-map key for use in storing/retrieving an
|
|
item from the identity map.
|
|
|
|
:param row: A :class:`.Row` instance. The columns which are
|
|
mapped by this :class:`_orm.Mapper` should be locatable in the row,
|
|
preferably via the :class:`_schema.Column`
|
|
object directly (as is the case
|
|
when a :func:`_expression.select` construct is executed), or
|
|
via string names of the form ``<tablename>_<colname>``.
|
|
|
|
"""
|
|
pk_cols = self.primary_key
|
|
if adapter:
|
|
pk_cols = [adapter.columns[c] for c in pk_cols]
|
|
|
|
return (
|
|
self._identity_class,
|
|
tuple(row[column] for column in pk_cols),
|
|
identity_token,
|
|
)
|
|
|
|
def identity_key_from_primary_key(self, primary_key, identity_token=None):
|
|
"""Return an identity-map key for use in storing/retrieving an
|
|
item from an identity map.
|
|
|
|
:param primary_key: A list of values indicating the identifier.
|
|
|
|
"""
|
|
return self._identity_class, tuple(primary_key), identity_token
|
|
|
|
def identity_key_from_instance(self, instance):
|
|
"""Return the identity key for the given instance, based on
|
|
its primary key attributes.
|
|
|
|
If the instance's state is expired, calling this method
|
|
will result in a database check to see if the object has been deleted.
|
|
If the row no longer exists,
|
|
:class:`~sqlalchemy.orm.exc.ObjectDeletedError` is raised.
|
|
|
|
This value is typically also found on the instance state under the
|
|
attribute name `key`.
|
|
|
|
"""
|
|
state = attributes.instance_state(instance)
|
|
return self._identity_key_from_state(state, attributes.PASSIVE_OFF)
|
|
|
|
def _identity_key_from_state(
|
|
self, state, passive=attributes.PASSIVE_RETURN_NO_VALUE
|
|
):
|
|
dict_ = state.dict
|
|
manager = state.manager
|
|
return (
|
|
self._identity_class,
|
|
tuple(
|
|
[
|
|
manager[prop.key].impl.get(state, dict_, passive)
|
|
for prop in self._identity_key_props
|
|
]
|
|
),
|
|
state.identity_token,
|
|
)
|
|
|
|
def primary_key_from_instance(self, instance):
|
|
"""Return the list of primary key values for the given
|
|
instance.
|
|
|
|
If the instance's state is expired, calling this method
|
|
will result in a database check to see if the object has been deleted.
|
|
If the row no longer exists,
|
|
:class:`~sqlalchemy.orm.exc.ObjectDeletedError` is raised.
|
|
|
|
"""
|
|
state = attributes.instance_state(instance)
|
|
identity_key = self._identity_key_from_state(
|
|
state, attributes.PASSIVE_OFF
|
|
)
|
|
return identity_key[1]
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _persistent_sortkey_fn(self):
|
|
key_fns = [col.type.sort_key_function for col in self.primary_key]
|
|
|
|
if set(key_fns).difference([None]):
|
|
|
|
def key(state):
|
|
return tuple(
|
|
key_fn(val) if key_fn is not None else val
|
|
for key_fn, val in zip(key_fns, state.key[1])
|
|
)
|
|
|
|
else:
|
|
|
|
def key(state):
|
|
return state.key[1]
|
|
|
|
return key
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _identity_key_props(self):
|
|
return [self._columntoproperty[col] for col in self.primary_key]
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _all_pk_cols(self):
|
|
collection = set()
|
|
for table in self.tables:
|
|
collection.update(self._pks_by_table[table])
|
|
return collection
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _should_undefer_in_wildcard(self):
|
|
cols = set(self.primary_key)
|
|
if self.polymorphic_on is not None:
|
|
cols.add(self.polymorphic_on)
|
|
return cols
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _primary_key_propkeys(self):
|
|
return {self._columntoproperty[col].key for col in self._all_pk_cols}
|
|
|
|
def _get_state_attr_by_column(
|
|
self, state, dict_, column, passive=attributes.PASSIVE_RETURN_NO_VALUE
|
|
):
|
|
prop = self._columntoproperty[column]
|
|
return state.manager[prop.key].impl.get(state, dict_, passive=passive)
|
|
|
|
def _set_committed_state_attr_by_column(self, state, dict_, column, value):
|
|
prop = self._columntoproperty[column]
|
|
state.manager[prop.key].impl.set_committed_value(state, dict_, value)
|
|
|
|
def _set_state_attr_by_column(self, state, dict_, column, value):
|
|
prop = self._columntoproperty[column]
|
|
state.manager[prop.key].impl.set(state, dict_, value, None)
|
|
|
|
def _get_committed_attr_by_column(self, obj, column):
|
|
state = attributes.instance_state(obj)
|
|
dict_ = attributes.instance_dict(obj)
|
|
return self._get_committed_state_attr_by_column(
|
|
state, dict_, column, passive=attributes.PASSIVE_OFF
|
|
)
|
|
|
|
def _get_committed_state_attr_by_column(
|
|
self, state, dict_, column, passive=attributes.PASSIVE_RETURN_NO_VALUE
|
|
):
|
|
|
|
prop = self._columntoproperty[column]
|
|
return state.manager[prop.key].impl.get_committed_value(
|
|
state, dict_, passive=passive
|
|
)
|
|
|
|
def _optimized_get_statement(self, state, attribute_names):
|
|
"""assemble a WHERE clause which retrieves a given state by primary
|
|
key, using a minimized set of tables.
|
|
|
|
Applies to a joined-table inheritance mapper where the
|
|
requested attribute names are only present on joined tables,
|
|
not the base table. The WHERE clause attempts to include
|
|
only those tables to minimize joins.
|
|
|
|
"""
|
|
props = self._props
|
|
|
|
col_attribute_names = set(attribute_names).intersection(
|
|
state.mapper.column_attrs.keys()
|
|
)
|
|
tables = set(
|
|
chain(
|
|
*[
|
|
sql_util.find_tables(c, check_columns=True)
|
|
for key in col_attribute_names
|
|
for c in props[key].columns
|
|
]
|
|
)
|
|
)
|
|
|
|
if self.base_mapper.local_table in tables:
|
|
return None
|
|
|
|
def visit_binary(binary):
|
|
leftcol = binary.left
|
|
rightcol = binary.right
|
|
if leftcol is None or rightcol is None:
|
|
return
|
|
|
|
if leftcol.table not in tables:
|
|
leftval = self._get_committed_state_attr_by_column(
|
|
state,
|
|
state.dict,
|
|
leftcol,
|
|
passive=attributes.PASSIVE_NO_INITIALIZE,
|
|
)
|
|
if leftval in orm_util._none_set:
|
|
raise _OptGetColumnsNotAvailable()
|
|
binary.left = sql.bindparam(
|
|
None, leftval, type_=binary.right.type
|
|
)
|
|
elif rightcol.table not in tables:
|
|
rightval = self._get_committed_state_attr_by_column(
|
|
state,
|
|
state.dict,
|
|
rightcol,
|
|
passive=attributes.PASSIVE_NO_INITIALIZE,
|
|
)
|
|
if rightval in orm_util._none_set:
|
|
raise _OptGetColumnsNotAvailable()
|
|
binary.right = sql.bindparam(
|
|
None, rightval, type_=binary.right.type
|
|
)
|
|
|
|
allconds = []
|
|
|
|
start = False
|
|
|
|
# as of #7507, from the lowest base table on upwards,
|
|
# we include all intermediary tables.
|
|
|
|
for mapper in reversed(list(self.iterate_to_root())):
|
|
if mapper.local_table in tables:
|
|
start = True
|
|
elif not isinstance(mapper.local_table, expression.TableClause):
|
|
return None
|
|
if start and not mapper.single:
|
|
allconds.append(mapper.inherit_condition)
|
|
tables.add(mapper.local_table)
|
|
|
|
# only the bottom table needs its criteria to be altered to fit
|
|
# the primary key ident - the rest of the tables upwards to the
|
|
# descendant-most class should all be present and joined to each
|
|
# other.
|
|
try:
|
|
allconds[0] = visitors.cloned_traverse(
|
|
allconds[0], {}, {"binary": visit_binary}
|
|
)
|
|
except _OptGetColumnsNotAvailable:
|
|
return None
|
|
|
|
cond = sql.and_(*allconds)
|
|
|
|
cols = []
|
|
for key in col_attribute_names:
|
|
cols.extend(props[key].columns)
|
|
return (
|
|
sql.select(*cols)
|
|
.where(cond)
|
|
.set_label_style(LABEL_STYLE_TABLENAME_PLUS_COL)
|
|
)
|
|
|
|
def _iterate_to_target_viawpoly(self, mapper):
|
|
if self.isa(mapper):
|
|
prev = self
|
|
for m in self.iterate_to_root():
|
|
yield m
|
|
|
|
if m is not prev and prev not in m._with_polymorphic_mappers:
|
|
break
|
|
|
|
prev = m
|
|
if m is mapper:
|
|
break
|
|
|
|
def _should_selectin_load(self, enabled_via_opt, polymorphic_from):
|
|
if not enabled_via_opt:
|
|
# common case, takes place for all polymorphic loads
|
|
mapper = polymorphic_from
|
|
for m in self._iterate_to_target_viawpoly(mapper):
|
|
if m.polymorphic_load == "selectin":
|
|
return m
|
|
else:
|
|
# uncommon case, selectin load options were used
|
|
enabled_via_opt = set(enabled_via_opt)
|
|
enabled_via_opt_mappers = {e.mapper: e for e in enabled_via_opt}
|
|
for entity in enabled_via_opt.union([polymorphic_from]):
|
|
mapper = entity.mapper
|
|
for m in self._iterate_to_target_viawpoly(mapper):
|
|
if (
|
|
m.polymorphic_load == "selectin"
|
|
or m in enabled_via_opt_mappers
|
|
):
|
|
return enabled_via_opt_mappers.get(m, m)
|
|
|
|
return None
|
|
|
|
@util.preload_module("sqlalchemy.orm.strategy_options")
|
|
def _subclass_load_via_in(self, entity):
|
|
"""Assemble a that can load the columns local to
|
|
this subclass as a SELECT with IN.
|
|
|
|
"""
|
|
strategy_options = util.preloaded.orm_strategy_options
|
|
|
|
assert self.inherits
|
|
|
|
if self.polymorphic_on is not None:
|
|
polymorphic_prop = self._columntoproperty[self.polymorphic_on]
|
|
keep_props = set([polymorphic_prop] + self._identity_key_props)
|
|
else:
|
|
keep_props = set(self._identity_key_props)
|
|
|
|
disable_opt = strategy_options.Load(entity)
|
|
enable_opt = strategy_options.Load(entity)
|
|
|
|
for prop in self.attrs:
|
|
if prop.parent is self or prop in keep_props:
|
|
# "enable" options, to turn on the properties that we want to
|
|
# load by default (subject to options from the query)
|
|
if not isinstance(prop, StrategizedProperty):
|
|
continue
|
|
|
|
enable_opt.set_generic_strategy(
|
|
# convert string name to an attribute before passing
|
|
# to loader strategy
|
|
(getattr(entity.entity_namespace, prop.key),),
|
|
dict(prop.strategy_key),
|
|
)
|
|
else:
|
|
# "disable" options, to turn off the properties from the
|
|
# superclass that we *don't* want to load, applied after
|
|
# the options from the query to override them
|
|
disable_opt.set_generic_strategy(
|
|
# convert string name to an attribute before passing
|
|
# to loader strategy
|
|
(getattr(entity.entity_namespace, prop.key),),
|
|
{"do_nothing": True},
|
|
)
|
|
|
|
primary_key = [
|
|
sql_util._deep_annotate(pk, {"_orm_adapt": True})
|
|
for pk in self.primary_key
|
|
]
|
|
|
|
if len(primary_key) > 1:
|
|
in_expr = sql.tuple_(*primary_key)
|
|
else:
|
|
in_expr = primary_key[0]
|
|
|
|
if entity.is_aliased_class:
|
|
assert entity.mapper is self
|
|
|
|
q = sql.select(entity).set_label_style(
|
|
LABEL_STYLE_TABLENAME_PLUS_COL
|
|
)
|
|
|
|
in_expr = entity._adapter.traverse(in_expr)
|
|
primary_key = [entity._adapter.traverse(k) for k in primary_key]
|
|
q = q.where(
|
|
in_expr.in_(sql.bindparam("primary_keys", expanding=True))
|
|
).order_by(*primary_key)
|
|
else:
|
|
|
|
q = sql.select(self).set_label_style(
|
|
LABEL_STYLE_TABLENAME_PLUS_COL
|
|
)
|
|
q = q.where(
|
|
in_expr.in_(sql.bindparam("primary_keys", expanding=True))
|
|
).order_by(*primary_key)
|
|
|
|
return q, enable_opt, disable_opt
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _subclass_load_via_in_mapper(self):
|
|
return self._subclass_load_via_in(self)
|
|
|
|
def cascade_iterator(self, type_, state, halt_on=None):
|
|
r"""Iterate each element and its mapper in an object graph,
|
|
for all relationships that meet the given cascade rule.
|
|
|
|
:param type\_:
|
|
The name of the cascade rule (i.e. ``"save-update"``, ``"delete"``,
|
|
etc.).
|
|
|
|
.. note:: the ``"all"`` cascade is not accepted here. For a generic
|
|
object traversal function, see :ref:`faq_walk_objects`.
|
|
|
|
:param state:
|
|
The lead InstanceState. child items will be processed per
|
|
the relationships defined for this object's mapper.
|
|
|
|
:return: the method yields individual object instances.
|
|
|
|
.. seealso::
|
|
|
|
:ref:`unitofwork_cascades`
|
|
|
|
:ref:`faq_walk_objects` - illustrates a generic function to
|
|
traverse all objects without relying on cascades.
|
|
|
|
"""
|
|
visited_states = set()
|
|
prp, mpp = object(), object()
|
|
|
|
assert state.mapper.isa(self)
|
|
|
|
visitables = deque(
|
|
[(deque(state.mapper._props.values()), prp, state, state.dict)]
|
|
)
|
|
|
|
while visitables:
|
|
iterator, item_type, parent_state, parent_dict = visitables[-1]
|
|
if not iterator:
|
|
visitables.pop()
|
|
continue
|
|
|
|
if item_type is prp:
|
|
prop = iterator.popleft()
|
|
if type_ not in prop.cascade:
|
|
continue
|
|
queue = deque(
|
|
prop.cascade_iterator(
|
|
type_,
|
|
parent_state,
|
|
parent_dict,
|
|
visited_states,
|
|
halt_on,
|
|
)
|
|
)
|
|
if queue:
|
|
visitables.append((queue, mpp, None, None))
|
|
elif item_type is mpp:
|
|
(
|
|
instance,
|
|
instance_mapper,
|
|
corresponding_state,
|
|
corresponding_dict,
|
|
) = iterator.popleft()
|
|
yield (
|
|
instance,
|
|
instance_mapper,
|
|
corresponding_state,
|
|
corresponding_dict,
|
|
)
|
|
visitables.append(
|
|
(
|
|
deque(instance_mapper._props.values()),
|
|
prp,
|
|
corresponding_state,
|
|
corresponding_dict,
|
|
)
|
|
)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _compiled_cache(self):
|
|
return util.LRUCache(self._compiled_cache_size)
|
|
|
|
@HasMemoized.memoized_attribute
|
|
def _sorted_tables(self):
|
|
table_to_mapper = {}
|
|
|
|
for mapper in self.base_mapper.self_and_descendants:
|
|
for t in mapper.tables:
|
|
table_to_mapper.setdefault(t, mapper)
|
|
|
|
extra_dependencies = []
|
|
for table, mapper in table_to_mapper.items():
|
|
super_ = mapper.inherits
|
|
if super_:
|
|
extra_dependencies.extend(
|
|
[(super_table, table) for super_table in super_.tables]
|
|
)
|
|
|
|
def skip(fk):
|
|
# attempt to skip dependencies that are not
|
|
# significant to the inheritance chain
|
|
# for two tables that are related by inheritance.
|
|
# while that dependency may be important, it's technically
|
|
# not what we mean to sort on here.
|
|
parent = table_to_mapper.get(fk.parent.table)
|
|
dep = table_to_mapper.get(fk.column.table)
|
|
if (
|
|
parent is not None
|
|
and dep is not None
|
|
and dep is not parent
|
|
and dep.inherit_condition is not None
|
|
):
|
|
cols = set(sql_util._find_columns(dep.inherit_condition))
|
|
if parent.inherit_condition is not None:
|
|
cols = cols.union(
|
|
sql_util._find_columns(parent.inherit_condition)
|
|
)
|
|
return fk.parent not in cols and fk.column not in cols
|
|
else:
|
|
return fk.parent not in cols
|
|
return False
|
|
|
|
sorted_ = sql_util.sort_tables(
|
|
table_to_mapper,
|
|
skip_fn=skip,
|
|
extra_dependencies=extra_dependencies,
|
|
)
|
|
|
|
ret = util.OrderedDict()
|
|
for t in sorted_:
|
|
ret[t] = table_to_mapper[t]
|
|
return ret
|
|
|
|
def _memo(self, key, callable_):
|
|
if key in self._memoized_values:
|
|
return self._memoized_values[key]
|
|
else:
|
|
self._memoized_values[key] = value = callable_()
|
|
return value
|
|
|
|
@util.memoized_property
|
|
def _table_to_equated(self):
|
|
"""memoized map of tables to collections of columns to be
|
|
synchronized upwards to the base mapper."""
|
|
|
|
result = util.defaultdict(list)
|
|
|
|
for table in self._sorted_tables:
|
|
cols = set(table.c)
|
|
for m in self.iterate_to_root():
|
|
if m._inherits_equated_pairs and cols.intersection(
|
|
util.reduce(
|
|
set.union,
|
|
[l.proxy_set for l, r in m._inherits_equated_pairs],
|
|
)
|
|
):
|
|
result[table].append((m, m._inherits_equated_pairs))
|
|
|
|
return result
|
|
|
|
|
|
class _OptGetColumnsNotAvailable(Exception):
|
|
pass
|
|
|
|
|
|
def configure_mappers():
|
|
"""Initialize the inter-mapper relationships of all mappers that
|
|
have been constructed thus far across all :class:`_orm.registry`
|
|
collections.
|
|
|
|
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.
|
|
|
|
Mapper configuration is normally invoked automatically, the first time
|
|
mappings from a particular :class:`_orm.registry` are used, as well as
|
|
whenever mappings are used and additional not-yet-configured mappers have
|
|
been constructed. The automatic configuration process however is local only
|
|
to the :class:`_orm.registry` involving the target mapper and any related
|
|
:class:`_orm.registry` objects which it may depend on; this is
|
|
equivalent to invoking the :meth:`_orm.registry.configure` method
|
|
on a particular :class:`_orm.registry`.
|
|
|
|
By contrast, the :func:`_orm.configure_mappers` function will invoke the
|
|
configuration process on all :class:`_orm.registry` objects that
|
|
exist in memory, and may be useful for scenarios where many individual
|
|
:class:`_orm.registry` objects that are nonetheless interrelated are
|
|
in use.
|
|
|
|
.. versionchanged:: 1.4
|
|
|
|
As of SQLAlchemy 1.4.0b2, this function works on a
|
|
per-:class:`_orm.registry` basis, locating all :class:`_orm.registry`
|
|
objects present and invoking the :meth:`_orm.registry.configure` method
|
|
on each. The :meth:`_orm.registry.configure` method may be preferred to
|
|
limit the configuration of mappers to those local to a particular
|
|
:class:`_orm.registry` and/or declarative base class.
|
|
|
|
Points at which automatic configuration is invoked include when a mapped
|
|
class is instantiated into an instance, as well as when ORM queries
|
|
are emitted using :meth:`.Session.query` or :meth:`_orm.Session.execute`
|
|
with an ORM-enabled statement.
|
|
|
|
The mapper configure process, whether invoked by
|
|
:func:`_orm.configure_mappers` or from :meth:`_orm.registry.configure`,
|
|
provides several event hooks that can be used to augment the mapper
|
|
configuration step. These hooks include:
|
|
|
|
* :meth:`.MapperEvents.before_configured` - called once before
|
|
:func:`.configure_mappers` or :meth:`_orm.registry.configure` does any
|
|
work; this can be used to establish additional options, properties, or
|
|
related mappings before the operation proceeds.
|
|
|
|
* :meth:`.MapperEvents.mapper_configured` - called as each individual
|
|
:class:`_orm.Mapper` is configured within the process; will include all
|
|
mapper state except for backrefs set up by other mappers that are still
|
|
to be configured.
|
|
|
|
* :meth:`.MapperEvents.after_configured` - called once after
|
|
:func:`.configure_mappers` or :meth:`_orm.registry.configure` is
|
|
complete; at this stage, all :class:`_orm.Mapper` objects that fall
|
|
within the scope of the configuration operation will be fully configured.
|
|
Note that the calling application may still have other mappings that
|
|
haven't been produced yet, such as if they are in modules as yet
|
|
unimported, and may also have mappings that are still to be configured,
|
|
if they are in other :class:`_orm.registry` collections not part of the
|
|
current scope of configuration.
|
|
|
|
"""
|
|
|
|
_configure_registries(_all_registries(), cascade=True)
|
|
|
|
|
|
def _configure_registries(registries, cascade):
|
|
for reg in registries:
|
|
if reg._new_mappers:
|
|
break
|
|
else:
|
|
return
|
|
|
|
with _CONFIGURE_MUTEX:
|
|
global _already_compiling
|
|
if _already_compiling:
|
|
return
|
|
_already_compiling = True
|
|
try:
|
|
|
|
# double-check inside mutex
|
|
for reg in registries:
|
|
if reg._new_mappers:
|
|
break
|
|
else:
|
|
return
|
|
|
|
Mapper.dispatch._for_class(Mapper).before_configured()
|
|
# initialize properties on all mappers
|
|
# note that _mapper_registry is unordered, which
|
|
# may randomly conceal/reveal issues related to
|
|
# the order of mapper compilation
|
|
|
|
_do_configure_registries(registries, cascade)
|
|
finally:
|
|
_already_compiling = False
|
|
Mapper.dispatch._for_class(Mapper).after_configured()
|
|
|
|
|
|
@util.preload_module("sqlalchemy.orm.decl_api")
|
|
def _do_configure_registries(registries, cascade):
|
|
|
|
registry = util.preloaded.orm_decl_api.registry
|
|
|
|
orig = set(registries)
|
|
|
|
for reg in registry._recurse_with_dependencies(registries):
|
|
has_skip = False
|
|
|
|
for mapper in reg._mappers_to_configure():
|
|
run_configure = None
|
|
for fn in mapper.dispatch.before_mapper_configured:
|
|
run_configure = fn(mapper, mapper.class_)
|
|
if run_configure is EXT_SKIP:
|
|
has_skip = True
|
|
break
|
|
if run_configure is EXT_SKIP:
|
|
continue
|
|
|
|
if getattr(mapper, "_configure_failed", False):
|
|
e = sa_exc.InvalidRequestError(
|
|
"One or more mappers failed to initialize - "
|
|
"can't proceed with initialization of other "
|
|
"mappers. Triggering mapper: '%s'. "
|
|
"Original exception was: %s"
|
|
% (mapper, mapper._configure_failed)
|
|
)
|
|
e._configure_failed = mapper._configure_failed
|
|
raise e
|
|
|
|
if not mapper.configured:
|
|
try:
|
|
mapper._post_configure_properties()
|
|
mapper._expire_memoizations()
|
|
mapper.dispatch.mapper_configured(mapper, mapper.class_)
|
|
except Exception:
|
|
exc = sys.exc_info()[1]
|
|
if not hasattr(exc, "_configure_failed"):
|
|
mapper._configure_failed = exc
|
|
raise
|
|
if not has_skip:
|
|
reg._new_mappers = False
|
|
|
|
if not cascade and reg._dependencies.difference(orig):
|
|
raise sa_exc.InvalidRequestError(
|
|
"configure was called with cascade=False but "
|
|
"additional registries remain"
|
|
)
|
|
|
|
|
|
@util.preload_module("sqlalchemy.orm.decl_api")
|
|
def _dispose_registries(registries, cascade):
|
|
|
|
registry = util.preloaded.orm_decl_api.registry
|
|
|
|
orig = set(registries)
|
|
|
|
for reg in registry._recurse_with_dependents(registries):
|
|
if not cascade and reg._dependents.difference(orig):
|
|
raise sa_exc.InvalidRequestError(
|
|
"Registry has dependent registries that are not disposed; "
|
|
"pass cascade=True to clear these also"
|
|
)
|
|
|
|
while reg._managers:
|
|
try:
|
|
manager, _ = reg._managers.popitem()
|
|
except KeyError:
|
|
# guard against race between while and popitem
|
|
pass
|
|
else:
|
|
reg._dispose_manager_and_mapper(manager)
|
|
|
|
reg._non_primary_mappers.clear()
|
|
reg._dependents.clear()
|
|
for dep in reg._dependencies:
|
|
dep._dependents.discard(reg)
|
|
reg._dependencies.clear()
|
|
# this wasn't done in the 1.3 clear_mappers() and in fact it
|
|
# was a bug, as it could cause configure_mappers() to invoke
|
|
# the "before_configured" event even though mappers had all been
|
|
# disposed.
|
|
reg._new_mappers = False
|
|
|
|
|
|
def reconstructor(fn):
|
|
"""Decorate a method as the 'reconstructor' hook.
|
|
|
|
Designates a single method as the "reconstructor", an ``__init__``-like
|
|
method that will be called by the ORM after the instance has been
|
|
loaded from the database or otherwise reconstituted.
|
|
|
|
The reconstructor will be invoked with no arguments. Scalar
|
|
(non-collection) database-mapped attributes of the instance will
|
|
be available for use within the function. Eagerly-loaded
|
|
collections are generally not yet available and will usually only
|
|
contain the first element. ORM state changes made to objects at
|
|
this stage will not be recorded for the next flush() operation, so
|
|
the activity within a reconstructor should be conservative.
|
|
|
|
.. seealso::
|
|
|
|
:ref:`mapping_constructors`
|
|
|
|
:meth:`.InstanceEvents.load`
|
|
|
|
"""
|
|
fn.__sa_reconstructor__ = True
|
|
return fn
|
|
|
|
|
|
def validates(*names, **kw):
|
|
r"""Decorate a method as a 'validator' for one or more named properties.
|
|
|
|
Designates a method as a validator, a method which receives the
|
|
name of the attribute as well as a value to be assigned, or in the
|
|
case of a collection, the value to be added to the collection.
|
|
The function can then raise validation exceptions to halt the
|
|
process from continuing (where Python's built-in ``ValueError``
|
|
and ``AssertionError`` exceptions are reasonable choices), or can
|
|
modify or replace the value before proceeding. The function should
|
|
otherwise return the given value.
|
|
|
|
Note that a validator for a collection **cannot** issue a load of that
|
|
collection within the validation routine - this usage raises
|
|
an assertion to avoid recursion overflows. This is a reentrant
|
|
condition which is not supported.
|
|
|
|
:param \*names: list of attribute names to be validated.
|
|
:param include_removes: if True, "remove" events will be
|
|
sent as well - the validation function must accept an additional
|
|
argument "is_remove" which will be a boolean.
|
|
|
|
:param include_backrefs: defaults to ``True``; if ``False``, the
|
|
validation function will not emit if the originator is an attribute
|
|
event related via a backref. This can be used for bi-directional
|
|
:func:`.validates` usage where only one validator should emit per
|
|
attribute operation.
|
|
|
|
.. versionadded:: 0.9.0
|
|
|
|
.. seealso::
|
|
|
|
:ref:`simple_validators` - usage examples for :func:`.validates`
|
|
|
|
"""
|
|
include_removes = kw.pop("include_removes", False)
|
|
include_backrefs = kw.pop("include_backrefs", True)
|
|
|
|
def wrap(fn):
|
|
fn.__sa_validators__ = names
|
|
fn.__sa_validation_opts__ = {
|
|
"include_removes": include_removes,
|
|
"include_backrefs": include_backrefs,
|
|
}
|
|
return fn
|
|
|
|
return wrap
|
|
|
|
|
|
def _event_on_load(state, ctx):
|
|
instrumenting_mapper = state.manager.mapper
|
|
|
|
if instrumenting_mapper._reconstructor:
|
|
instrumenting_mapper._reconstructor(state.obj())
|
|
|
|
|
|
def _event_on_init(state, args, kwargs):
|
|
"""Run init_instance hooks.
|
|
|
|
This also includes mapper compilation, normally not needed
|
|
here but helps with some piecemeal configuration
|
|
scenarios (such as in the ORM tutorial).
|
|
|
|
"""
|
|
|
|
instrumenting_mapper = state.manager.mapper
|
|
if instrumenting_mapper:
|
|
instrumenting_mapper._check_configure()
|
|
if instrumenting_mapper._set_polymorphic_identity:
|
|
instrumenting_mapper._set_polymorphic_identity(state)
|
|
|
|
|
|
class _ColumnMapping(dict):
|
|
"""Error reporting helper for mapper._columntoproperty."""
|
|
|
|
__slots__ = ("mapper",)
|
|
|
|
def __init__(self, mapper):
|
|
# TODO: weakref would be a good idea here
|
|
self.mapper = mapper
|
|
|
|
def __missing__(self, column):
|
|
prop = self.mapper._props.get(column)
|
|
if prop:
|
|
raise orm_exc.UnmappedColumnError(
|
|
"Column '%s.%s' is not available, due to "
|
|
"conflicting property '%s':%r"
|
|
% (column.table.name, column.name, column.key, prop)
|
|
)
|
|
raise orm_exc.UnmappedColumnError(
|
|
"No column %s is configured on mapper %s..."
|
|
% (column, self.mapper)
|
|
)
|