SQLAlchemy 1.1 Documentation
ORM Exceptions¶
SQLAlchemy ORM exceptions.
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sqlalchemy.orm.exc.
ConcurrentModificationError
¶ alias of
StaleDataError
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exception
sqlalchemy.orm.exc.
DetachedInstanceError
¶ An attempt to access unloaded attributes on a mapped instance that is detached.
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exception
sqlalchemy.orm.exc.
FlushError
¶ A invalid condition was detected during flush().
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exception
sqlalchemy.orm.exc.
MultipleResultsFound
¶ A single database result was required but more than one were found.
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sqlalchemy.orm.exc.
NO_STATE
= (<type 'exceptions.AttributeError'>, <type 'exceptions.KeyError'>)¶ Exception types that may be raised by instrumentation implementations.
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exception
sqlalchemy.orm.exc.
NoResultFound
¶ A database result was required but none was found.
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exception
sqlalchemy.orm.exc.
ObjectDeletedError
(state, msg=None)¶ 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
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.
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exception
sqlalchemy.orm.exc.
ObjectDereferencedError
¶ An operation cannot complete due to an object being garbage collected.
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exception
sqlalchemy.orm.exc.
StaleDataError
¶ 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”.
버전 0.7.4에 추가.
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exception
sqlalchemy.orm.exc.
UnmappedClassError
(cls, msg=None)¶ An mapping operation was requested for an unknown class.
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exception
sqlalchemy.orm.exc.
UnmappedColumnError
¶ Mapping operation was requested on an unknown column.
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exception
sqlalchemy.orm.exc.
UnmappedError
¶ Base for exceptions that involve expected mappings not present.
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exception
sqlalchemy.orm.exc.
UnmappedInstanceError
(obj, msg=None)¶ An mapping operation was requested for an unknown instance.