Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/sqlalchemy/orm/exc.py: 43%
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« prev ^ index » next coverage.py v7.2.7, created at 2023-06-07 06:35 +0000
1# orm/exc.py
2# Copyright (C) 2005-2023 the SQLAlchemy authors and contributors
3# <see AUTHORS file>
4#
5# This module is part of SQLAlchemy and is released under
6# the MIT License: https://www.opensource.org/licenses/mit-license.php
8"""SQLAlchemy ORM exceptions."""
9from .. import exc as sa_exc
10from .. import util
11from ..exc import MultipleResultsFound # noqa
12from ..exc import NoResultFound # noqa
15NO_STATE = (AttributeError, KeyError)
16"""Exception types that may be raised by instrumentation implementations."""
19class StaleDataError(sa_exc.SQLAlchemyError):
20 """An operation encountered database state that is unaccounted for.
22 Conditions which cause this to happen include:
24 * A flush may have attempted to update or delete rows
25 and an unexpected number of rows were matched during
26 the UPDATE or DELETE statement. Note that when
27 version_id_col is used, rows in UPDATE or DELETE statements
28 are also matched against the current known version
29 identifier.
31 * A mapped object with version_id_col was refreshed,
32 and the version number coming back from the database does
33 not match that of the object itself.
35 * A object is detached from its parent object, however
36 the object was previously attached to a different parent
37 identity which was garbage collected, and a decision
38 cannot be made if the new parent was really the most
39 recent "parent".
41 """
44ConcurrentModificationError = StaleDataError
47class FlushError(sa_exc.SQLAlchemyError):
48 """A invalid condition was detected during flush()."""
51class UnmappedError(sa_exc.InvalidRequestError):
52 """Base for exceptions that involve expected mappings not present."""
55class ObjectDereferencedError(sa_exc.SQLAlchemyError):
56 """An operation cannot complete due to an object being garbage
57 collected.
59 """
62class DetachedInstanceError(sa_exc.SQLAlchemyError):
63 """An attempt to access unloaded attributes on a
64 mapped instance that is detached."""
66 code = "bhk3"
69class UnmappedInstanceError(UnmappedError):
70 """An mapping operation was requested for an unknown instance."""
72 @util.preload_module("sqlalchemy.orm.base")
73 def __init__(self, obj, msg=None):
74 base = util.preloaded.orm_base
76 if not msg:
77 try:
78 base.class_mapper(type(obj))
79 name = _safe_cls_name(type(obj))
80 msg = (
81 "Class %r is mapped, but this instance lacks "
82 "instrumentation. This occurs when the instance "
83 "is created before sqlalchemy.orm.mapper(%s) "
84 "was called." % (name, name)
85 )
86 except UnmappedClassError:
87 msg = _default_unmapped(type(obj))
88 if isinstance(obj, type):
89 msg += (
90 "; was a class (%s) supplied where an instance was "
91 "required?" % _safe_cls_name(obj)
92 )
93 UnmappedError.__init__(self, msg)
95 def __reduce__(self):
96 return self.__class__, (None, self.args[0])
99class UnmappedClassError(UnmappedError):
100 """An mapping operation was requested for an unknown class."""
102 def __init__(self, cls, msg=None):
103 if not msg:
104 msg = _default_unmapped(cls)
105 UnmappedError.__init__(self, msg)
107 def __reduce__(self):
108 return self.__class__, (None, self.args[0])
111class ObjectDeletedError(sa_exc.InvalidRequestError):
112 """A refresh operation failed to retrieve the database
113 row corresponding to an object's known primary key identity.
115 A refresh operation proceeds when an expired attribute is
116 accessed on an object, or when :meth:`_query.Query.get` is
117 used to retrieve an object which is, upon retrieval, detected
118 as expired. A SELECT is emitted for the target row
119 based on primary key; if no row is returned, this
120 exception is raised.
122 The true meaning of this exception is simply that
123 no row exists for the primary key identifier associated
124 with a persistent object. The row may have been
125 deleted, or in some cases the primary key updated
126 to a new value, outside of the ORM's management of the target
127 object.
129 """
131 @util.preload_module("sqlalchemy.orm.base")
132 def __init__(self, state, msg=None):
133 base = util.preloaded.orm_base
135 if not msg:
136 msg = (
137 "Instance '%s' has been deleted, or its "
138 "row is otherwise not present." % base.state_str(state)
139 )
141 sa_exc.InvalidRequestError.__init__(self, msg)
143 def __reduce__(self):
144 return self.__class__, (None, self.args[0])
147class UnmappedColumnError(sa_exc.InvalidRequestError):
148 """Mapping operation was requested on an unknown column."""
151class LoaderStrategyException(sa_exc.InvalidRequestError):
152 """A loader strategy for an attribute does not exist."""
154 def __init__(
155 self,
156 applied_to_property_type,
157 requesting_property,
158 applies_to,
159 actual_strategy_type,
160 strategy_key,
161 ):
162 if actual_strategy_type is None:
163 sa_exc.InvalidRequestError.__init__(
164 self,
165 "Can't find strategy %s for %s"
166 % (strategy_key, requesting_property),
167 )
168 else:
169 sa_exc.InvalidRequestError.__init__(
170 self,
171 'Can\'t apply "%s" strategy to property "%s", '
172 'which is a "%s"; this loader strategy is intended '
173 'to be used with a "%s".'
174 % (
175 util.clsname_as_plain_name(actual_strategy_type),
176 requesting_property,
177 util.clsname_as_plain_name(applied_to_property_type),
178 util.clsname_as_plain_name(applies_to),
179 ),
180 )
183def _safe_cls_name(cls):
184 try:
185 cls_name = ".".join((cls.__module__, cls.__name__))
186 except AttributeError:
187 cls_name = getattr(cls, "__name__", None)
188 if cls_name is None:
189 cls_name = repr(cls)
190 return cls_name
193@util.preload_module("sqlalchemy.orm.base")
194def _default_unmapped(cls):
195 base = util.preloaded.orm_base
197 try:
198 mappers = base.manager_of_class(cls).mappers
199 except (TypeError,) + NO_STATE:
200 mappers = {}
201 name = _safe_cls_name(cls)
203 if not mappers:
204 return "Class '%s' is not mapped" % name