3177 lines
123 KiB
Python
3177 lines
123 KiB
Python
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# orm/mapper.py
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# Copyright (C) 2005-2018 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: http://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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import types
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import weakref
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from itertools import chain
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from collections import deque
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from .. import sql, util, log, exc as sa_exc, event, schema, inspection
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from ..sql import expression, visitors, operators, util as sql_util
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from . import instrumentation, attributes, exc as orm_exc, loading
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from . import properties
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from . import util as orm_util
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from .interfaces import MapperProperty, InspectionAttr, _MappedAttribute
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from .base import _class_to_mapper, _state_mapper, class_mapper, \
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state_str, _INSTRUMENTOR
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from .path_registry import PathRegistry
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import sys
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_mapper_registry = weakref.WeakKeyDictionary()
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_already_compiling = False
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_memoized_configured_property = util.group_expirable_memoized_property()
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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(InspectionAttr):
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"""Define the correlation of class attributes to database table
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columns.
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The :class:`.Mapper` object is instantiated using the
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:func:`~sqlalchemy.orm.mapper` function. For information
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about instantiating new :class:`.Mapper` objects, see
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that function's documentation.
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When :func:`.mapper` is used
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explicitly to link a user defined class with table
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metadata, this is referred to as *classical mapping*.
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Modern SQLAlchemy usage tends to favor the
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:mod:`sqlalchemy.ext.declarative` extension for class
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configuration, which
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makes usage of :func:`.mapper` behind the scenes.
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Given a particular class known to be mapped by the ORM,
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the :class:`.Mapper` which maintains it can be acquired
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using the :func:`.inspect` function::
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from sqlalchemy import inspect
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mapper = inspect(MyClass)
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A class which was mapped by the :mod:`sqlalchemy.ext.declarative`
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extension will also have its mapper available via the ``__mapper__``
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attribute.
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"""
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_new_mappers = False
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def __init__(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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extension=None,
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order_by=False,
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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"""Return a new :class:`~.Mapper` object.
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This function is typically used behind the scenes
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via the Declarative extension. When using Declarative,
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many of the usual :func:`.mapper` arguments are handled
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by the Declarative extension itself, including ``class_``,
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``local_table``, ``properties``, and ``inherits``.
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Other options are passed to :func:`.mapper` using
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the ``__mapper_args__`` class variable::
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class MyClass(Base):
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__tablename__ = 'my_table'
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id = Column(Integer, primary_key=True)
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type = Column(String(50))
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alt = Column("some_alt", Integer)
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__mapper_args__ = {
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'polymorphic_on' : type
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}
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Explicit use of :func:`.mapper`
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is often referred to as *classical mapping*. The above
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declarative example is equivalent in classical form to::
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my_table = Table("my_table", metadata,
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Column('id', Integer, primary_key=True),
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Column('type', String(50)),
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Column("some_alt", Integer)
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)
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class MyClass(object):
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pass
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mapper(MyClass, my_table,
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polymorphic_on=my_table.c.type,
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properties={
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'alt':my_table.c.some_alt
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})
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.. seealso::
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:ref:`classical_mapping` - discussion of direct usage of
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:func:`.mapper`
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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:`.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:`.Table` produced as a result of the ``__tablename__``
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and :class:`.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.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:`.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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.. 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 extension: A :class:`.MapperExtension` instance or
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list of :class:`.MapperExtension` instances which will be applied
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to all operations by this :class:`.Mapper`. **Deprecated.**
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Please see :class:`.MapperEvents`.
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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 :class:`.Mapper`
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of one indicating a superclass to which this :class:`.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:`.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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orphanable 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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.. versionadded:: 0.8 - the consideration of a pending object as
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an "orphan" has been modified to more closely match the
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behavior as that of persistent objects, which is that the object
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is expunged from the :class:`.Session` as soon as it is
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de-associated from any of its orphan-enabled parents. Previously,
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the pending object would be expunged only if de-associated
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from all of its orphan-enabled parents. The new flag
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``legacy_is_orphan`` is added to :func:`.orm.mapper` which
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re-establishes the legacy behavior.
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:param non_primary: Specify that this :class:`.Mapper` is in addition
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to the "primary" mapper, that is, the one used for persistence.
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The :class:`.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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:paramref:`.Mapper.non_primary` is not an often used option, but
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is useful in some specific :func:`.relationship` cases.
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.. seealso::
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:ref:`relationship_non_primary_mapper`
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:param order_by: A single :class:`.Column` or list of :class:`.Column`
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objects for which selection operations should use as the default
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ordering for entities. By default mappers have no pre-defined
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ordering.
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.. deprecated:: 1.1 The :paramref:`.Mapper.order_by` parameter
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is deprecated. Use :meth:`.Query.order_by` to determine the
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ordering of a result set.
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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:`.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
|
||
|
|
on joined-table rows.
|
||
|
|
|
||
|
|
When False, it is assumed that the database does not enforce
|
||
|
|
referential integrity and will not be issuing its own CASCADE
|
||
|
|
operation for an update. The unit of work process will
|
||
|
|
emit an UPDATE statement for the dependent columns during a
|
||
|
|
primary key change.
|
||
|
|
|
||
|
|
.. seealso::
|
||
|
|
|
||
|
|
:ref:`passive_updates` - description of a similar feature as
|
||
|
|
used with :func:`.relationship`
|
||
|
|
|
||
|
|
:paramref:`.mapper.passive_deletes` - supporting ON DELETE
|
||
|
|
CASCADE for joined-table inheritance mappers
|
||
|
|
|
||
|
|
:param polymorphic_load: Specifies "polymorphic loading" behavior
|
||
|
|
for a subclass in an inheritance hierarchy (joined and single
|
||
|
|
table inheritance only). Valid values are:
|
||
|
|
|
||
|
|
* "'inline'" - specifies this class should be part of the
|
||
|
|
"with_polymorphic" mappers, e.g. its columns will be included
|
||
|
|
in a SELECT query against the base.
|
||
|
|
|
||
|
|
* "'selectin'" - specifies that when instances of this class
|
||
|
|
are loaded, an additional SELECT will be emitted to retrieve
|
||
|
|
the columns specific to this subclass. The SELECT uses
|
||
|
|
IN to fetch multiple subclasses at once.
|
||
|
|
|
||
|
|
.. versionadded:: 1.2
|
||
|
|
|
||
|
|
.. seealso::
|
||
|
|
|
||
|
|
:ref:`with_polymorphic_mapper_config`
|
||
|
|
|
||
|
|
:ref:`polymorphic_selectin`
|
||
|
|
|
||
|
|
:param polymorphic_on: Specifies the column, attribute, or
|
||
|
|
SQL expression used to determine the target class for an
|
||
|
|
incoming row, when inheriting classes are present.
|
||
|
|
|
||
|
|
This value is commonly a :class:`.Column` object that's
|
||
|
|
present in the mapped :class:`.Table`::
|
||
|
|
|
||
|
|
class Employee(Base):
|
||
|
|
__tablename__ = 'employee'
|
||
|
|
|
||
|
|
id = Column(Integer, primary_key=True)
|
||
|
|
discriminator = Column(String(50))
|
||
|
|
|
||
|
|
__mapper_args__ = {
|
||
|
|
"polymorphic_on":discriminator,
|
||
|
|
"polymorphic_identity":"employee"
|
||
|
|
}
|
||
|
|
|
||
|
|
It may also be specified
|
||
|
|
as a SQL expression, as in this example where we
|
||
|
|
use the :func:`.case` construct to provide a conditional
|
||
|
|
approach::
|
||
|
|
|
||
|
|
class Employee(Base):
|
||
|
|
__tablename__ = 'employee'
|
||
|
|
|
||
|
|
id = Column(Integer, primary_key=True)
|
||
|
|
discriminator = Column(String(50))
|
||
|
|
|
||
|
|
__mapper_args__ = {
|
||
|
|
"polymorphic_on":case([
|
||
|
|
(discriminator == "EN", "engineer"),
|
||
|
|
(discriminator == "MA", "manager"),
|
||
|
|
], else_="employee"),
|
||
|
|
"polymorphic_identity":"employee"
|
||
|
|
}
|
||
|
|
|
||
|
|
It may also refer to any attribute
|
||
|
|
configured with :func:`.column_property`, or to the
|
||
|
|
string name of one::
|
||
|
|
|
||
|
|
class Employee(Base):
|
||
|
|
__tablename__ = 'employee'
|
||
|
|
|
||
|
|
id = Column(Integer, primary_key=True)
|
||
|
|
discriminator = Column(String(50))
|
||
|
|
employee_type = column_property(
|
||
|
|
case([
|
||
|
|
(discriminator == "EN", "engineer"),
|
||
|
|
(discriminator == "MA", "manager"),
|
||
|
|
], else_="employee")
|
||
|
|
)
|
||
|
|
|
||
|
|
__mapper_args__ = {
|
||
|
|
"polymorphic_on":employee_type,
|
||
|
|
"polymorphic_identity":"employee"
|
||
|
|
}
|
||
|
|
|
||
|
|
.. versionchanged:: 0.7.4
|
||
|
|
``polymorphic_on`` may be specified as a SQL expression,
|
||
|
|
or refer to any attribute configured with
|
||
|
|
:func:`.column_property`, or to the string name of one.
|
||
|
|
|
||
|
|
When setting ``polymorphic_on`` to reference an
|
||
|
|
attribute or expression that's not present in the
|
||
|
|
locally mapped :class:`.Table`, yet the value
|
||
|
|
of the discriminator should be persisted to the database,
|
||
|
|
the value of the
|
||
|
|
discriminator is not automatically set on new
|
||
|
|
instances; this must be handled by the user,
|
||
|
|
either through manual means or via event listeners.
|
||
|
|
A typical approach to establishing such a listener
|
||
|
|
looks like::
|
||
|
|
|
||
|
|
from sqlalchemy import event
|
||
|
|
from sqlalchemy.orm import object_mapper
|
||
|
|
|
||
|
|
@event.listens_for(Employee, "init", propagate=True)
|
||
|
|
def set_identity(instance, *arg, **kw):
|
||
|
|
mapper = object_mapper(instance)
|
||
|
|
instance.discriminator = mapper.polymorphic_identity
|
||
|
|
|
||
|
|
Where above, we assign the value of ``polymorphic_identity``
|
||
|
|
for the mapped class to the ``discriminator`` attribute,
|
||
|
|
thus persisting the value to the ``discriminator`` column
|
||
|
|
in the database.
|
||
|
|
|
||
|
|
.. warning::
|
||
|
|
|
||
|
|
Currently, **only one discriminator column may be set**, typically
|
||
|
|
on the base-most class in the hierarchy. "Cascading" polymorphic
|
||
|
|
columns are not yet supported.
|
||
|
|
|
||
|
|
.. seealso::
|
||
|
|
|
||
|
|
:ref:`inheritance_toplevel`
|
||
|
|
|
||
|
|
:param polymorphic_identity: Specifies the value which
|
||
|
|
identifies this particular class as returned by the
|
||
|
|
column expression referred to by the ``polymorphic_on``
|
||
|
|
setting. As rows are received, the value corresponding
|
||
|
|
to the ``polymorphic_on`` column expression is compared
|
||
|
|
to this value, indicating which subclass should
|
||
|
|
be used for the newly reconstructed object.
|
||
|
|
|
||
|
|
:param properties: A dictionary mapping the string names of object
|
||
|
|
attributes to :class:`.MapperProperty` instances, which define the
|
||
|
|
persistence behavior of that attribute. Note that :class:`.Column`
|
||
|
|
objects present in
|
||
|
|
the mapped :class:`.Table` are automatically placed into
|
||
|
|
``ColumnProperty`` instances upon mapping, unless overridden.
|
||
|
|
When using Declarative, this argument is passed automatically,
|
||
|
|
based on all those :class:`.MapperProperty` instances declared
|
||
|
|
in the declared class body.
|
||
|
|
|
||
|
|
:param primary_key: A list of :class:`.Column` objects which define
|
||
|
|
the primary key to be used against this mapper's selectable unit.
|
||
|
|
This is normally simply the primary key of the ``local_table``, but
|
||
|
|
can be overridden here.
|
||
|
|
|
||
|
|
:param version_id_col: A :class:`.Column`
|
||
|
|
that will be used to keep a running version id of rows
|
||
|
|
in the table. This is used to detect concurrent updates or
|
||
|
|
the presence of stale data in a flush. The methodology is to
|
||
|
|
detect if an UPDATE statement does not match the last known
|
||
|
|
version id, a
|
||
|
|
: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.class_manager = None
|
||
|
|
|
||
|
|
self._primary_key_argument = util.to_list(primary_key)
|
||
|
|
self.non_primary = non_primary
|
||
|
|
|
||
|
|
if order_by is not False:
|
||
|
|
self.order_by = util.to_list(order_by)
|
||
|
|
util.warn_deprecated(
|
||
|
|
"Mapper.order_by is deprecated."
|
||
|
|
"Use Query.order_by() in order to affect the ordering of ORM "
|
||
|
|
"result sets.")
|
||
|
|
|
||
|
|
else:
|
||
|
|
self.order_by = order_by
|
||
|
|
|
||
|
|
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
|
||
|
|
self.local_table = local_table
|
||
|
|
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 = expression._clause_element_as_expr(
|
||
|
|
polymorphic_on)
|
||
|
|
self._dependency_processors = []
|
||
|
|
self.validators = util.immutabledict()
|
||
|
|
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._deprecated_extensions = util.to_list(extension or [])
|
||
|
|
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
|
||
|
|
|
||
|
|
if isinstance(self.local_table, expression.SelectBase):
|
||
|
|
raise sa_exc.InvalidRequestError(
|
||
|
|
"When mapping against a select() construct, map against "
|
||
|
|
"an alias() of the construct instead."
|
||
|
|
"This because several databases don't allow a "
|
||
|
|
"SELECT from a subquery that does not have an alias."
|
||
|
|
)
|
||
|
|
|
||
|
|
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
|
||
|
|
|
||
|
|
self.configured = False
|
||
|
|
|
||
|
|
# prevent this mapper from being constructed
|
||
|
|
# while a configure_mappers() is occurring (and defer a
|
||
|
|
# configure_mappers() until construction succeeds)
|
||
|
|
_CONFIGURE_MUTEX.acquire()
|
||
|
|
try:
|
||
|
|
self.dispatch._events._new_mapper_instance(class_, self)
|
||
|
|
self._configure_inheritance()
|
||
|
|
self._configure_legacy_instrument_class()
|
||
|
|
self._configure_class_instrumentation()
|
||
|
|
self._configure_listeners()
|
||
|
|
self._configure_properties()
|
||
|
|
self._configure_polymorphic_setter()
|
||
|
|
self._configure_pks()
|
||
|
|
Mapper._new_mappers = True
|
||
|
|
self._log("constructed")
|
||
|
|
self._expire_memoizations()
|
||
|
|
finally:
|
||
|
|
_CONFIGURE_MUTEX.release()
|
||
|
|
|
||
|
|
# 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
|
||
|
|
|
||
|
|
@property
|
||
|
|
def entity(self):
|
||
|
|
r"""Part of the inspection API.
|
||
|
|
|
||
|
|
Returns self.class\_.
|
||
|
|
|
||
|
|
"""
|
||
|
|
return self.class_
|
||
|
|
|
||
|
|
local_table = None
|
||
|
|
"""The :class:`.Selectable` which this :class:`.Mapper` manages.
|
||
|
|
|
||
|
|
Typically is an instance of :class:`.Table` or :class:`.Alias`.
|
||
|
|
May also be ``None``.
|
||
|
|
|
||
|
|
The "local" table is the
|
||
|
|
selectable that the :class:`.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:`.Mapper` represents. If this mapper is a
|
||
|
|
single-table inheriting mapper, local_table will be ``None``.
|
||
|
|
|
||
|
|
.. seealso::
|
||
|
|
|
||
|
|
:attr:`~.Mapper.mapped_table`.
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
mapped_table = None
|
||
|
|
"""The :class:`.Selectable` to which this :class:`.Mapper` is mapped.
|
||
|
|
|
||
|
|
Typically an instance of :class:`.Table`, :class:`.Join`, or
|
||
|
|
:class:`.Alias`.
|
||
|
|
|
||
|
|
The "mapped" table is the selectable that
|
||
|
|
the mapper selects from during queries. For non-inheriting
|
||
|
|
mappers, the mapped table is the same as the "local" table.
|
||
|
|
For joined-table inheritance mappers, mapped_table references the
|
||
|
|
full :class:`.Join` representing full rows for this particular
|
||
|
|
subclass. For single-table inheritance mappers, mapped_table
|
||
|
|
references the base table.
|
||
|
|
|
||
|
|
.. seealso::
|
||
|
|
|
||
|
|
:attr:`~.Mapper.local_table`.
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
inherits = None
|
||
|
|
"""References the :class:`.Mapper` which this :class:`.Mapper`
|
||
|
|
inherits from, if any.
|
||
|
|
|
||
|
|
This is a *read only* attribute determined during mapper construction.
|
||
|
|
Behavior is undefined if directly modified.
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
configured = None
|
||
|
|
"""Represent ``True`` if this :class:`.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:`.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:`.Table` objects
|
||
|
|
which this :class:`.Mapper` is aware of.
|
||
|
|
|
||
|
|
If the mapper is mapped to a :class:`.Join`, or an :class:`.Alias`
|
||
|
|
representing a :class:`.Select`, the individual :class:`.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:`.Column` objects
|
||
|
|
which comprise the 'primary key' of the mapped table, from the
|
||
|
|
perspective of this :class:`.Mapper`.
|
||
|
|
|
||
|
|
This list is against the selectable in :attr:`~.Mapper.mapped_table`. In
|
||
|
|
the case of inheriting mappers, some columns may be managed by a
|
||
|
|
superclass mapper. For example, in the case of a :class:`.Join`, the
|
||
|
|
primary key is determined by all of the primary key columns across all
|
||
|
|
tables referenced by the :class:`.Join`.
|
||
|
|
|
||
|
|
The list is also not necessarily the same as the primary key column
|
||
|
|
collection associated with the underlying tables; the :class:`.Mapper`
|
||
|
|
features a ``primary_key`` argument that can override what the
|
||
|
|
:class:`.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:`.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:`.Mapper`.
|
||
|
|
|
||
|
|
This is a *read only* attribute determined during mapper construction.
|
||
|
|
Behavior is undefined if directly modified.
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
single = None
|
||
|
|
"""Represent ``True`` if this :class:`.Mapper` is a single table
|
||
|
|
inheritance mapper.
|
||
|
|
|
||
|
|
:attr:`~.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:`.Mapper` is a "non-primary"
|
||
|
|
mapper, e.g. a mapper that is used only to selet 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:`.Column` or SQL expression specified as the
|
||
|
|
``polymorphic_on`` argument
|
||
|
|
for this :class:`.Mapper`, within an inheritance scenario.
|
||
|
|
|
||
|
|
This attribute is normally a :class:`.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:`.Mapper` instances, within an inheritance scenario.
|
||
|
|
|
||
|
|
The identifiers can be of any type which is comparable to the
|
||
|
|
type of column represented by :attr:`~.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:`~.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:`~.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:`.Mapper` in an inheritance chain.
|
||
|
|
|
||
|
|
In a non-inheriting scenario, this attribute will always be this
|
||
|
|
:class:`.Mapper`. In an inheritance scenario, it references
|
||
|
|
the :class:`.Mapper` which is parent to all other :class:`.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:`.Column` or other scalar expression
|
||
|
|
objects maintained by this :class:`.Mapper`.
|
||
|
|
|
||
|
|
The collection behaves the same as that of the ``c`` attribute on
|
||
|
|
any :class:`.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:`.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:`~.Mapper.columns`."""
|
||
|
|
|
||
|
|
@util.memoized_property
|
||
|
|
def _path_registry(self):
|
||
|
|
return PathRegistry.per_mapper(self)
|
||
|
|
|
||
|
|
def _configure_inheritance(self):
|
||
|
|
"""Configure settings related to inherting 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__))
|
||
|
|
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.mapped_table = self.inherits.mapped_table
|
||
|
|
self.single = True
|
||
|
|
elif self.local_table is not self.inherits.local_table:
|
||
|
|
if self.concrete:
|
||
|
|
self.mapped_table = 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)
|
||
|
|
self.inherit_condition = sql_util.join_condition(
|
||
|
|
self.inherits.local_table,
|
||
|
|
self.local_table)
|
||
|
|
self.mapped_table = sql.join(
|
||
|
|
self.inherits.mapped_table,
|
||
|
|
self.local_table,
|
||
|
|
self.inherit_condition)
|
||
|
|
|
||
|
|
fks = util.to_set(self.inherit_foreign_keys)
|
||
|
|
self._inherits_equated_pairs = \
|
||
|
|
sql_util.criterion_as_pairs(
|
||
|
|
self.mapped_table.onclause,
|
||
|
|
consider_as_foreign_keys=fks)
|
||
|
|
else:
|
||
|
|
self.mapped_table = 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)
|
||
|
|
)
|
||
|
|
|
||
|
|
if self.order_by is False and \
|
||
|
|
not self.concrete and \
|
||
|
|
self.inherits.order_by is not False:
|
||
|
|
self.order_by = self.inherits.order_by
|
||
|
|
|
||
|
|
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 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.mapped_table = self.local_table
|
||
|
|
if self.polymorphic_identity is not None:
|
||
|
|
self.polymorphic_map[self.polymorphic_identity] = self
|
||
|
|
self._identity_class = self.class_
|
||
|
|
|
||
|
|
if self.mapped_table is None:
|
||
|
|
raise sa_exc.ArgumentError(
|
||
|
|
"Mapper '%s' does not have a mapped_table 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 isinstance(self.local_table, expression.SelectBase):
|
||
|
|
raise sa_exc.InvalidRequestError(
|
||
|
|
"When mapping against a select() construct, map against "
|
||
|
|
"an alias() of the construct instead."
|
||
|
|
"This because several databases don't allow a "
|
||
|
|
"SELECT from a subquery that does not have an alias."
|
||
|
|
)
|
||
|
|
|
||
|
|
if self.with_polymorphic and \
|
||
|
|
isinstance(self.with_polymorphic[1],
|
||
|
|
expression.SelectBase):
|
||
|
|
self.with_polymorphic = (self.with_polymorphic[0],
|
||
|
|
self.with_polymorphic[1].alias())
|
||
|
|
|
||
|
|
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:`.Mapper` as the 'inherits' for this
|
||
|
|
:class:`.Mapper`, assuming this :class:`.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_legacy_instrument_class(self):
|
||
|
|
|
||
|
|
if self.inherits:
|
||
|
|
self.dispatch._update(self.inherits.dispatch)
|
||
|
|
super_extensions = set(
|
||
|
|
chain(*[m._deprecated_extensions
|
||
|
|
for m in self.inherits.iterate_to_root()]))
|
||
|
|
else:
|
||
|
|
super_extensions = set()
|
||
|
|
|
||
|
|
for ext in self._deprecated_extensions:
|
||
|
|
if ext not in super_extensions:
|
||
|
|
ext._adapt_instrument_class(self, ext)
|
||
|
|
|
||
|
|
def _configure_listeners(self):
|
||
|
|
if self.inherits:
|
||
|
|
super_extensions = set(
|
||
|
|
chain(*[m._deprecated_extensions
|
||
|
|
for m in self.inherits.iterate_to_root()]))
|
||
|
|
else:
|
||
|
|
super_extensions = set()
|
||
|
|
|
||
|
|
for ext in self._deprecated_extensions:
|
||
|
|
if ext not in super_extensions:
|
||
|
|
ext._adapt_listener(self, ext)
|
||
|
|
|
||
|
|
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.
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
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._identity_class = manager.mapper._identity_class
|
||
|
|
_mapper_registry[self] = True
|
||
|
|
return
|
||
|
|
|
||
|
|
if manager is not None:
|
||
|
|
assert manager.class_ is self.class_
|
||
|
|
if manager.is_mapped:
|
||
|
|
raise sa_exc.ArgumentError(
|
||
|
|
"Class '%s' already has a primary mapper defined. "
|
||
|
|
"Use non_primary=True to "
|
||
|
|
"create a non primary Mapper. clear_mappers() will "
|
||
|
|
"remove *all* current mappers from all classes." %
|
||
|
|
self.class_)
|
||
|
|
# else:
|
||
|
|
# a ClassManager may already exist as
|
||
|
|
# ClassManager.instrument_attribute() creates
|
||
|
|
# new managers for each subclass if they don't yet exist.
|
||
|
|
|
||
|
|
_mapper_registry[self] = True
|
||
|
|
|
||
|
|
# note: this *must be called before instrumentation.register_class*
|
||
|
|
# to maintain the documented behavior of instrument_class
|
||
|
|
self.dispatch.instrument_class(self, self.class_)
|
||
|
|
|
||
|
|
if manager is None:
|
||
|
|
manager = instrumentation.register_class(self.class_)
|
||
|
|
|
||
|
|
self.class_manager = manager
|
||
|
|
|
||
|
|
manager.mapper = self
|
||
|
|
manager.deferred_scalar_loader = util.partial(
|
||
|
|
loading.load_scalar_attributes, self)
|
||
|
|
|
||
|
|
# The remaining members can be added by any mapper,
|
||
|
|
# e_name None or not.
|
||
|
|
if manager.info.get(_INSTRUMENTOR, False):
|
||
|
|
return
|
||
|
|
|
||
|
|
event.listen(manager, 'first_init', _event_on_first_init, raw=True)
|
||
|
|
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 isinstance(method, types.MethodType):
|
||
|
|
method = method.im_func
|
||
|
|
if isinstance(method, types.FunctionType):
|
||
|
|
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)}
|
||
|
|
)
|
||
|
|
|
||
|
|
manager.info[_INSTRUMENTOR] = self
|
||
|
|
|
||
|
|
@classmethod
|
||
|
|
def _configure_all(cls):
|
||
|
|
"""Class-level path to the :func:`.configure_mappers` call.
|
||
|
|
"""
|
||
|
|
configure_mappers()
|
||
|
|
|
||
|
|
def dispose(self):
|
||
|
|
# Disable any attribute-based compilation.
|
||
|
|
self.configured = True
|
||
|
|
|
||
|
|
if hasattr(self, '_configure_failed'):
|
||
|
|
del self._configure_failed
|
||
|
|
|
||
|
|
if not self.non_primary and \
|
||
|
|
self.class_manager is not None and \
|
||
|
|
self.class_manager.is_mapped and \
|
||
|
|
self.class_manager.mapper is self:
|
||
|
|
instrumentation.unregister_class(self.class_)
|
||
|
|
|
||
|
|
def _configure_pks(self):
|
||
|
|
self.tables = sql_util.find_tables(self.mapped_table)
|
||
|
|
|
||
|
|
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.mapped_table])
|
||
|
|
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.mapped_table not in self._pks_by_table or \
|
||
|
|
len(self._pks_by_table[self.mapped_table]) == 0:
|
||
|
|
raise sa_exc.ArgumentError(
|
||
|
|
"Mapper %s could not assemble any primary "
|
||
|
|
"key columns for mapped table '%s'" %
|
||
|
|
(self, self.mapped_table.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 mapped_table pks -
|
||
|
|
# reduce to the minimal set of columns
|
||
|
|
if self._primary_key_argument:
|
||
|
|
primary_key = sql_util.reduce_columns(
|
||
|
|
[self.mapped_table.corresponding_column(c) for c in
|
||
|
|
self._primary_key_argument],
|
||
|
|
ignore_nonexistent_tables=True)
|
||
|
|
else:
|
||
|
|
primary_key = sql_util.reduce_columns(
|
||
|
|
self._pks_by_table[self.mapped_table],
|
||
|
|
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.mapped_table.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):
|
||
|
|
# Column and other ClauseElement objects which are mapped
|
||
|
|
self.columns = self.c = util.OrderedProperties()
|
||
|
|
|
||
|
|
# object attribute names mapped to MapperProperty objects
|
||
|
|
self._props = util.OrderedDict()
|
||
|
|
|
||
|
|
# table columns mapped to lists of MapperProperty objects
|
||
|
|
# using a list allows a single column to be defined as
|
||
|
|
# populating multiple object attributes
|
||
|
|
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.mapped_table.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:
|
||
|
|
raise sa_exc.ArgumentError(
|
||
|
|
"Can't determine polymorphic_on "
|
||
|
|
"value '%s' - no attribute is "
|
||
|
|
"mapped to this name." % self.polymorphic_on)
|
||
|
|
|
||
|
|
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
|
||
|
|
elif not expression._is_column(self.polymorphic_on):
|
||
|
|
# polymorphic_on is not a Column and not a ColumnProperty;
|
||
|
|
# not supported right now.
|
||
|
|
raise sa_exc.ArgumentError(
|
||
|
|
"Only direct column-mapped "
|
||
|
|
"property or SQL expression "
|
||
|
|
"can be passed for 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 mapped_table
|
||
|
|
col = self.mapped_table.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 mapped_table 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.mapped_table is mapper.mapped_table:
|
||
|
|
self.polymorphic_on = mapper.polymorphic_on
|
||
|
|
else:
|
||
|
|
self.polymorphic_on = \
|
||
|
|
self.mapped_table.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
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def _version_id_prop(self):
|
||
|
|
if self.version_id_col is not None:
|
||
|
|
return self._columntoproperty[self.version_id_col]
|
||
|
|
else:
|
||
|
|
return None
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def _acceptable_polymorphic_identities(self):
|
||
|
|
identities = set()
|
||
|
|
|
||
|
|
stack = deque([self])
|
||
|
|
while stack:
|
||
|
|
item = stack.popleft()
|
||
|
|
if item.mapped_table is self.mapped_table:
|
||
|
|
identities.add(item.polymorphic_identity)
|
||
|
|
stack.extend(item._inheriting_mappers)
|
||
|
|
|
||
|
|
return identities
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def _prop_set(self):
|
||
|
|
return frozenset(self._props.values())
|
||
|
|
|
||
|
|
def _adapt_inherited_property(self, key, prop, init):
|
||
|
|
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,
|
||
|
|
properties.ConcreteInheritedProperty(),
|
||
|
|
init=init, setparent=True)
|
||
|
|
|
||
|
|
def _configure_property(self, key, prop, init=True, setparent=True):
|
||
|
|
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.mapped_table.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.mapped_table._reset_exported()
|
||
|
|
col = self.mapped_table.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)
|
||
|
|
|
||
|
|
self.columns[key] = col
|
||
|
|
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,
|
||
|
|
properties.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()
|
||
|
|
|
||
|
|
def _property_from_column(self, key, prop):
|
||
|
|
"""generate/update a :class:`.ColumnProprerty` given a
|
||
|
|
:class:`.Column` object. """
|
||
|
|
|
||
|
|
# we were passed a Column or a list of Columns;
|
||
|
|
# generate a properties.ColumnProperty
|
||
|
|
columns = util.to_list(prop)
|
||
|
|
column = columns[0]
|
||
|
|
if not expression._is_column(column):
|
||
|
|
raise sa_exc.ArgumentError(
|
||
|
|
"%s=%r is not an instance of MapperProperty or Column"
|
||
|
|
% (key, prop))
|
||
|
|
|
||
|
|
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,
|
||
|
|
properties.ConcreteInheritedProperty):
|
||
|
|
mapped_column = []
|
||
|
|
for c in columns:
|
||
|
|
mc = self.mapped_table.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.mapped_table._reset_exported()
|
||
|
|
mc = self.mapped_table.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 _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():
|
||
|
|
_memoized_configured_property.expire_instance(mapper)
|
||
|
|
|
||
|
|
@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 "Mapper|%s|%s%s" % (
|
||
|
|
self.class_.__name__,
|
||
|
|
self.local_table is not None and
|
||
|
|
self.local_table.description or None,
|
||
|
|
self.non_primary and "|non-primary" or ""
|
||
|
|
)
|
||
|
|
|
||
|
|
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 and Mapper._new_mappers:
|
||
|
|
configure_mappers()
|
||
|
|
|
||
|
|
try:
|
||
|
|
return self._props[key]
|
||
|
|
except KeyError:
|
||
|
|
raise sa_exc.InvalidRequestError(
|
||
|
|
"Mapper '%s' has no property '%s'" % (self, key))
|
||
|
|
|
||
|
|
def get_property_by_column(self, column):
|
||
|
|
"""Given a :class:`.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."""
|
||
|
|
if Mapper._new_mappers:
|
||
|
|
configure_mappers()
|
||
|
|
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.mapped_table
|
||
|
|
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
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def _single_table_criterion(self):
|
||
|
|
if self.single and \
|
||
|
|
self.inherits and \
|
||
|
|
self.polymorphic_on is not None:
|
||
|
|
return self.polymorphic_on.in_(
|
||
|
|
m.polymorphic_identity
|
||
|
|
for m in self.self_and_descendants)
|
||
|
|
else:
|
||
|
|
return None
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def _with_polymorphic_mappers(self):
|
||
|
|
if Mapper._new_mappers:
|
||
|
|
configure_mappers()
|
||
|
|
if not self.with_polymorphic:
|
||
|
|
return []
|
||
|
|
return self._mappers_from_spec(*self.with_polymorphic)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def _with_polymorphic_selectable(self):
|
||
|
|
if not self.with_polymorphic:
|
||
|
|
return self.mapped_table
|
||
|
|
|
||
|
|
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:`.Mapper` objects included in the
|
||
|
|
default "polymorphic" query.
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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()
|
||
|
|
)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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()
|
||
|
|
)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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()
|
||
|
|
)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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()
|
||
|
|
)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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()
|
||
|
|
)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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()
|
||
|
|
)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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()
|
||
|
|
)
|
||
|
|
|
||
|
|
@property
|
||
|
|
def selectable(self):
|
||
|
|
"""The :func:`.select` construct this :class:`.Mapper` selects from
|
||
|
|
by default.
|
||
|
|
|
||
|
|
Normally, this is equivalent to :attr:`.mapped_table`, 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 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)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def _polymorphic_properties(self):
|
||
|
|
return list(self._iterate_polymorphic_properties(
|
||
|
|
self._with_polymorphic_mappers))
|
||
|
|
|
||
|
|
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
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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:`.Mapper` has several pre-filtered views
|
||
|
|
of this attribute which limit the types of properties
|
||
|
|
returned, inclding :attr:`.synonyms`, :attr:`.column_attrs`,
|
||
|
|
:attr:`.relationships`, and :attr:`.composites`.
|
||
|
|
|
||
|
|
.. warning::
|
||
|
|
|
||
|
|
The :attr:`.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:`.Mapper.all_orm_descriptors`
|
||
|
|
|
||
|
|
"""
|
||
|
|
if Mapper._new_mappers:
|
||
|
|
configure_mappers()
|
||
|
|
return util.ImmutableProperties(self._props)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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.
|
||
|
|
|
||
|
|
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:`.Mapper.attrs`.
|
||
|
|
|
||
|
|
.. warning::
|
||
|
|
|
||
|
|
The :attr:`.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.
|
||
|
|
|
||
|
|
.. versionadded:: 0.8.0
|
||
|
|
|
||
|
|
.. seealso::
|
||
|
|
|
||
|
|
:attr:`.Mapper.attrs`
|
||
|
|
|
||
|
|
"""
|
||
|
|
return util.ImmutableProperties(
|
||
|
|
dict(self.class_manager._all_sqla_attributes()))
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def synonyms(self):
|
||
|
|
"""Return a namespace of all :class:`.SynonymProperty`
|
||
|
|
properties maintained by this :class:`.Mapper`.
|
||
|
|
|
||
|
|
.. seealso::
|
||
|
|
|
||
|
|
:attr:`.Mapper.attrs` - namespace of all :class:`.MapperProperty`
|
||
|
|
objects.
|
||
|
|
|
||
|
|
"""
|
||
|
|
return self._filter_properties(properties.SynonymProperty)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def column_attrs(self):
|
||
|
|
"""Return a namespace of all :class:`.ColumnProperty`
|
||
|
|
properties maintained by this :class:`.Mapper`.
|
||
|
|
|
||
|
|
.. seealso::
|
||
|
|
|
||
|
|
:attr:`.Mapper.attrs` - namespace of all :class:`.MapperProperty`
|
||
|
|
objects.
|
||
|
|
|
||
|
|
"""
|
||
|
|
return self._filter_properties(properties.ColumnProperty)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def relationships(self):
|
||
|
|
"""A namespace of all :class:`.RelationshipProperty` properties
|
||
|
|
maintained by this :class:`.Mapper`.
|
||
|
|
|
||
|
|
.. warning::
|
||
|
|
|
||
|
|
the :attr:`.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:`.Mapper.attrs` - namespace of all :class:`.MapperProperty`
|
||
|
|
objects.
|
||
|
|
|
||
|
|
"""
|
||
|
|
return self._filter_properties(properties.RelationshipProperty)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def composites(self):
|
||
|
|
"""Return a namespace of all :class:`.CompositeProperty`
|
||
|
|
properties maintained by this :class:`.Mapper`.
|
||
|
|
|
||
|
|
.. seealso::
|
||
|
|
|
||
|
|
:attr:`.Mapper.attrs` - namespace of all :class:`.MapperProperty`
|
||
|
|
objects.
|
||
|
|
|
||
|
|
"""
|
||
|
|
return self._filter_properties(properties.CompositeProperty)
|
||
|
|
|
||
|
|
def _filter_properties(self, type_):
|
||
|
|
if Mapper._new_mappers:
|
||
|
|
configure_mappers()
|
||
|
|
return util.ImmutableProperties(util.OrderedDict(
|
||
|
|
(k, v) for k, v in self._props.items()
|
||
|
|
if isinstance(v, type_)
|
||
|
|
))
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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(None, type_=primary_key.type))
|
||
|
|
for primary_key in self.primary_key]
|
||
|
|
return sql.and_(*[k == v for (k, v) in params]), \
|
||
|
|
util.column_dict(params)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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, i.e.
|
||
|
|
|
||
|
|
{
|
||
|
|
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, obj):
|
||
|
|
if isinstance(obj, (_MappedAttribute,
|
||
|
|
instrumentation.ClassManager,
|
||
|
|
expression.ColumnElement)):
|
||
|
|
return False
|
||
|
|
else:
|
||
|
|
return True
|
||
|
|
|
||
|
|
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
|
||
|
|
if local:
|
||
|
|
if self.class_.__dict__.get(assigned_name, None) is not None \
|
||
|
|
and self._is_userland_descriptor(
|
||
|
|
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(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 _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
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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]
|
||
|
|
for col in pk_cols:
|
||
|
|
if not result._has_key(col):
|
||
|
|
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:`.RowProxy` instance. The columns which are
|
||
|
|
mapped by this :class:`.Mapper` should be locatable in the row,
|
||
|
|
preferably via the :class:`.Column` object directly (as is the case
|
||
|
|
when a :func:`.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_NEVER_SET):
|
||
|
|
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]
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def _identity_key_props(self):
|
||
|
|
return [self._columntoproperty[col] for col in self.primary_key]
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def _all_pk_props(self):
|
||
|
|
collection = set()
|
||
|
|
for table in self.tables:
|
||
|
|
collection.update(self._pks_by_table[table])
|
||
|
|
return collection
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def _primary_key_propkeys(self):
|
||
|
|
return {prop.key for prop in self._all_pk_props}
|
||
|
|
|
||
|
|
def _get_state_attr_by_column(
|
||
|
|
self, state, dict_, column,
|
||
|
|
passive=attributes.PASSIVE_RETURN_NEVER_SET):
|
||
|
|
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_NEVER_SET):
|
||
|
|
|
||
|
|
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
|
||
|
|
|
||
|
|
tables = set(chain(
|
||
|
|
*[sql_util.find_tables(c, check_columns=True)
|
||
|
|
for key in attribute_names
|
||
|
|
for c in props[key].columns]
|
||
|
|
))
|
||
|
|
|
||
|
|
if self.base_mapper.local_table in tables:
|
||
|
|
return None
|
||
|
|
|
||
|
|
class ColumnsNotAvailable(Exception):
|
||
|
|
pass
|
||
|
|
|
||
|
|
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 ColumnsNotAvailable()
|
||
|
|
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 ColumnsNotAvailable()
|
||
|
|
binary.right = sql.bindparam(None, rightval,
|
||
|
|
type_=binary.right.type)
|
||
|
|
|
||
|
|
allconds = []
|
||
|
|
|
||
|
|
try:
|
||
|
|
start = False
|
||
|
|
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(visitors.cloned_traverse(
|
||
|
|
mapper.inherit_condition,
|
||
|
|
{},
|
||
|
|
{'binary': visit_binary}
|
||
|
|
)
|
||
|
|
)
|
||
|
|
except ColumnsNotAvailable:
|
||
|
|
return None
|
||
|
|
|
||
|
|
cond = sql.and_(*allconds)
|
||
|
|
|
||
|
|
cols = []
|
||
|
|
for key in attribute_names:
|
||
|
|
cols.extend(props[key].columns)
|
||
|
|
return sql.select(cols, cond, use_labels=True)
|
||
|
|
|
||
|
|
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.dependencies(
|
||
|
|
"sqlalchemy.ext.baked",
|
||
|
|
"sqlalchemy.orm.strategy_options")
|
||
|
|
def _subclass_load_via_in(self, baked, strategy_options, entity):
|
||
|
|
"""Assemble a BakedQuery that can load the columns local to
|
||
|
|
this subclass as a SELECT with IN.
|
||
|
|
|
||
|
|
"""
|
||
|
|
assert self.inherits
|
||
|
|
|
||
|
|
polymorphic_prop = self._columntoproperty[
|
||
|
|
self.polymorphic_on]
|
||
|
|
keep_props = set(
|
||
|
|
[polymorphic_prop] + 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)
|
||
|
|
enable_opt.set_generic_strategy(
|
||
|
|
(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(
|
||
|
|
(prop.key, ),
|
||
|
|
{"do_nothing": True}
|
||
|
|
)
|
||
|
|
|
||
|
|
if len(self.primary_key) > 1:
|
||
|
|
in_expr = sql.tuple_(*self.primary_key)
|
||
|
|
else:
|
||
|
|
in_expr = self.primary_key[0]
|
||
|
|
|
||
|
|
if entity.is_aliased_class:
|
||
|
|
assert entity.mapper is self
|
||
|
|
q = baked.BakedQuery(
|
||
|
|
self._compiled_cache,
|
||
|
|
lambda session: session.query(entity).
|
||
|
|
select_entity_from(entity.selectable)._adapt_all_clauses(),
|
||
|
|
(self, )
|
||
|
|
)
|
||
|
|
q.spoil()
|
||
|
|
else:
|
||
|
|
q = baked.BakedQuery(
|
||
|
|
self._compiled_cache,
|
||
|
|
lambda session: session.query(self),
|
||
|
|
(self, )
|
||
|
|
)
|
||
|
|
|
||
|
|
q += lambda q: q.filter(
|
||
|
|
in_expr.in_(
|
||
|
|
sql.bindparam('primary_keys', expanding=True)
|
||
|
|
)
|
||
|
|
).order_by(*self.primary_key)
|
||
|
|
|
||
|
|
return q, enable_opt, disable_opt
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def _subclass_load_via_in_mapper(self):
|
||
|
|
return self._subclass_load_via_in(self)
|
||
|
|
|
||
|
|
def cascade_iterator(self, type_, state, halt_on=None):
|
||
|
|
"""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
|
||
|
|
)
|
||
|
|
)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
def _compiled_cache(self):
|
||
|
|
return util.LRUCache(self._compiled_cache_size)
|
||
|
|
|
||
|
|
@_memoized_configured_property
|
||
|
|
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
|
||
|
|
|
||
|
|
|
||
|
|
def configure_mappers():
|
||
|
|
"""Initialize the inter-mapper relationships of all mappers that
|
||
|
|
have been constructed thus far.
|
||
|
|
|
||
|
|
This function can be called any number of times, but in
|
||
|
|
most cases is invoked automatically, the first time mappings are used,
|
||
|
|
as well as whenever mappings are used and additional not-yet-configured
|
||
|
|
mappers have been constructed.
|
||
|
|
|
||
|
|
Points at which this occur include when a mapped class is instantiated
|
||
|
|
into an instance, as well as when the :meth:`.Session.query` method
|
||
|
|
is used.
|
||
|
|
|
||
|
|
The :func:`.configure_mappers` function provides several event hooks
|
||
|
|
that can be used to augment its functionality. These methods include:
|
||
|
|
|
||
|
|
* :meth:`.MapperEvents.before_configured` - called once before
|
||
|
|
:func:`.configure_mappers` 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 indivudal
|
||
|
|
:class:`.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` is complete; at this stage, all
|
||
|
|
:class:`.Mapper` objects that are known to SQLAlchemy 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.
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
if not Mapper._new_mappers:
|
||
|
|
return
|
||
|
|
|
||
|
|
_CONFIGURE_MUTEX.acquire()
|
||
|
|
try:
|
||
|
|
global _already_compiling
|
||
|
|
if _already_compiling:
|
||
|
|
return
|
||
|
|
_already_compiling = True
|
||
|
|
try:
|
||
|
|
|
||
|
|
# double-check inside mutex
|
||
|
|
if not Mapper._new_mappers:
|
||
|
|
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
|
||
|
|
|
||
|
|
for mapper in list(_mapper_registry):
|
||
|
|
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
|
||
|
|
|
||
|
|
Mapper._new_mappers = False
|
||
|
|
finally:
|
||
|
|
_already_compiling = False
|
||
|
|
finally:
|
||
|
|
_CONFIGURE_MUTEX.release()
|
||
|
|
Mapper.dispatch._for_class(Mapper).after_configured()
|
||
|
|
|
||
|
|
|
||
|
|
def reconstructor(fn):
|
||
|
|
"""Decorate a method as the 'reconstructor' hook.
|
||
|
|
|
||
|
|
Designates a 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.
|
||
|
|
|
||
|
|
.. versionadded:: 0.7.7
|
||
|
|
: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.info[_INSTRUMENTOR]
|
||
|
|
if instrumenting_mapper._reconstructor:
|
||
|
|
instrumenting_mapper._reconstructor(state.obj())
|
||
|
|
|
||
|
|
|
||
|
|
def _event_on_first_init(manager, cls):
|
||
|
|
"""Initial mapper compilation trigger.
|
||
|
|
|
||
|
|
instrumentation calls this one when InstanceState
|
||
|
|
is first generated, and is needed for legacy mutable
|
||
|
|
attributes to work.
|
||
|
|
"""
|
||
|
|
|
||
|
|
instrumenting_mapper = manager.info.get(_INSTRUMENTOR)
|
||
|
|
if instrumenting_mapper:
|
||
|
|
if Mapper._new_mappers:
|
||
|
|
configure_mappers()
|
||
|
|
|
||
|
|
|
||
|
|
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.info.get(_INSTRUMENTOR)
|
||
|
|
if instrumenting_mapper:
|
||
|
|
if Mapper._new_mappers:
|
||
|
|
configure_mappers()
|
||
|
|
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):
|
||
|
|
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))
|