You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
205 lines
6.4 KiB
Python
205 lines
6.4 KiB
Python
# orm/exc.py
|
|
# Copyright (C) 2005-2022 the SQLAlchemy authors and contributors
|
|
# <see AUTHORS file>
|
|
#
|
|
# This module is part of SQLAlchemy and is released under
|
|
# the MIT License: https://www.opensource.org/licenses/mit-license.php
|
|
|
|
"""SQLAlchemy ORM exceptions."""
|
|
from .. import exc as sa_exc
|
|
from .. import util
|
|
from ..exc import MultipleResultsFound # noqa
|
|
from ..exc import NoResultFound # noqa
|
|
|
|
|
|
NO_STATE = (AttributeError, KeyError)
|
|
"""Exception types that may be raised by instrumentation implementations."""
|
|
|
|
|
|
class StaleDataError(sa_exc.SQLAlchemyError):
|
|
"""An operation encountered database state that is unaccounted for.
|
|
|
|
Conditions which cause this to happen include:
|
|
|
|
* A flush may have attempted to update or delete rows
|
|
and an unexpected number of rows were matched during
|
|
the UPDATE or DELETE statement. Note that when
|
|
version_id_col is used, rows in UPDATE or DELETE statements
|
|
are also matched against the current known version
|
|
identifier.
|
|
|
|
* A mapped object with version_id_col was refreshed,
|
|
and the version number coming back from the database does
|
|
not match that of the object itself.
|
|
|
|
* A object is detached from its parent object, however
|
|
the object was previously attached to a different parent
|
|
identity which was garbage collected, and a decision
|
|
cannot be made if the new parent was really the most
|
|
recent "parent".
|
|
|
|
"""
|
|
|
|
|
|
ConcurrentModificationError = StaleDataError
|
|
|
|
|
|
class FlushError(sa_exc.SQLAlchemyError):
|
|
"""A invalid condition was detected during flush()."""
|
|
|
|
|
|
class UnmappedError(sa_exc.InvalidRequestError):
|
|
"""Base for exceptions that involve expected mappings not present."""
|
|
|
|
|
|
class ObjectDereferencedError(sa_exc.SQLAlchemyError):
|
|
"""An operation cannot complete due to an object being garbage
|
|
collected.
|
|
|
|
"""
|
|
|
|
|
|
class DetachedInstanceError(sa_exc.SQLAlchemyError):
|
|
"""An attempt to access unloaded attributes on a
|
|
mapped instance that is detached."""
|
|
|
|
code = "bhk3"
|
|
|
|
|
|
class UnmappedInstanceError(UnmappedError):
|
|
"""An mapping operation was requested for an unknown instance."""
|
|
|
|
@util.preload_module("sqlalchemy.orm.base")
|
|
def __init__(self, obj, msg=None):
|
|
base = util.preloaded.orm_base
|
|
|
|
if not msg:
|
|
try:
|
|
base.class_mapper(type(obj))
|
|
name = _safe_cls_name(type(obj))
|
|
msg = (
|
|
"Class %r is mapped, but this instance lacks "
|
|
"instrumentation. This occurs when the instance "
|
|
"is created before sqlalchemy.orm.mapper(%s) "
|
|
"was called." % (name, name)
|
|
)
|
|
except UnmappedClassError:
|
|
msg = _default_unmapped(type(obj))
|
|
if isinstance(obj, type):
|
|
msg += (
|
|
"; was a class (%s) supplied where an instance was "
|
|
"required?" % _safe_cls_name(obj)
|
|
)
|
|
UnmappedError.__init__(self, msg)
|
|
|
|
def __reduce__(self):
|
|
return self.__class__, (None, self.args[0])
|
|
|
|
|
|
class UnmappedClassError(UnmappedError):
|
|
"""An mapping operation was requested for an unknown class."""
|
|
|
|
def __init__(self, cls, msg=None):
|
|
if not msg:
|
|
msg = _default_unmapped(cls)
|
|
UnmappedError.__init__(self, msg)
|
|
|
|
def __reduce__(self):
|
|
return self.__class__, (None, self.args[0])
|
|
|
|
|
|
class ObjectDeletedError(sa_exc.InvalidRequestError):
|
|
"""A refresh operation failed to retrieve the database
|
|
row corresponding to an object's known primary key identity.
|
|
|
|
A refresh operation proceeds when an expired attribute is
|
|
accessed on an object, or when :meth:`_query.Query.get` is
|
|
used to retrieve an object which is, upon retrieval, detected
|
|
as expired. A SELECT is emitted for the target row
|
|
based on primary key; if no row is returned, this
|
|
exception is raised.
|
|
|
|
The true meaning of this exception is simply that
|
|
no row exists for the primary key identifier associated
|
|
with a persistent object. The row may have been
|
|
deleted, or in some cases the primary key updated
|
|
to a new value, outside of the ORM's management of the target
|
|
object.
|
|
|
|
"""
|
|
|
|
@util.preload_module("sqlalchemy.orm.base")
|
|
def __init__(self, state, msg=None):
|
|
base = util.preloaded.orm_base
|
|
|
|
if not msg:
|
|
msg = (
|
|
"Instance '%s' has been deleted, or its "
|
|
"row is otherwise not present." % base.state_str(state)
|
|
)
|
|
|
|
sa_exc.InvalidRequestError.__init__(self, msg)
|
|
|
|
def __reduce__(self):
|
|
return self.__class__, (None, self.args[0])
|
|
|
|
|
|
class UnmappedColumnError(sa_exc.InvalidRequestError):
|
|
"""Mapping operation was requested on an unknown column."""
|
|
|
|
|
|
class LoaderStrategyException(sa_exc.InvalidRequestError):
|
|
"""A loader strategy for an attribute does not exist."""
|
|
|
|
def __init__(
|
|
self,
|
|
applied_to_property_type,
|
|
requesting_property,
|
|
applies_to,
|
|
actual_strategy_type,
|
|
strategy_key,
|
|
):
|
|
if actual_strategy_type is None:
|
|
sa_exc.InvalidRequestError.__init__(
|
|
self,
|
|
"Can't find strategy %s for %s"
|
|
% (strategy_key, requesting_property),
|
|
)
|
|
else:
|
|
sa_exc.InvalidRequestError.__init__(
|
|
self,
|
|
'Can\'t apply "%s" strategy to property "%s", '
|
|
'which is a "%s"; this loader strategy is intended '
|
|
'to be used with a "%s".'
|
|
% (
|
|
util.clsname_as_plain_name(actual_strategy_type),
|
|
requesting_property,
|
|
util.clsname_as_plain_name(applied_to_property_type),
|
|
util.clsname_as_plain_name(applies_to),
|
|
),
|
|
)
|
|
|
|
|
|
def _safe_cls_name(cls):
|
|
try:
|
|
cls_name = ".".join((cls.__module__, cls.__name__))
|
|
except AttributeError:
|
|
cls_name = getattr(cls, "__name__", None)
|
|
if cls_name is None:
|
|
cls_name = repr(cls)
|
|
return cls_name
|
|
|
|
|
|
@util.preload_module("sqlalchemy.orm.base")
|
|
def _default_unmapped(cls):
|
|
base = util.preloaded.orm_base
|
|
|
|
try:
|
|
mappers = base.manager_of_class(cls).mappers
|
|
except (TypeError,) + NO_STATE:
|
|
mappers = {}
|
|
name = _safe_cls_name(cls)
|
|
|
|
if not mappers:
|
|
return "Class '%s' is not mapped" % name
|