99 lines
3.1 KiB
Python
99 lines
3.1 KiB
Python
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# exc.py - ORM exceptions
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# Copyright (C) the SQLAlchemy authors and contributors
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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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"""SQLAlchemy ORM exceptions."""
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import sqlalchemy as sa
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NO_STATE = (AttributeError, KeyError)
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"""Exception types that may be raised by instrumentation implementations."""
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class ConcurrentModificationError(sa.exc.SQLAlchemyError):
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"""Rows have been modified outside of the unit of work."""
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class FlushError(sa.exc.SQLAlchemyError):
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"""A invalid condition was detected during flush()."""
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class UnmappedError(sa.exc.InvalidRequestError):
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"""TODO"""
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class DetachedInstanceError(sa.exc.SQLAlchemyError):
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"""An attempt to access unloaded attributes on a mapped instance that is detached."""
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class UnmappedInstanceError(UnmappedError):
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"""An mapping operation was requested for an unknown instance."""
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def __init__(self, obj, msg=None):
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if not msg:
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try:
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mapper = sa.orm.class_mapper(type(obj))
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name = _safe_cls_name(type(obj))
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msg = ("Class %r is mapped, but this instance lacks "
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"instrumentation. This occurs when the instance is created "
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"before sqlalchemy.orm.mapper(%s) was called." % (name, name))
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except UnmappedClassError:
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msg = _default_unmapped(type(obj))
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if isinstance(obj, type):
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msg += (
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'; was a class (%s) supplied where an instance was '
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'required?' % _safe_cls_name(obj))
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UnmappedError.__init__(self, msg)
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class UnmappedClassError(UnmappedError):
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"""An mapping operation was requested for an unknown class."""
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def __init__(self, cls, msg=None):
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if not msg:
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msg = _default_unmapped(cls)
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UnmappedError.__init__(self, msg)
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class ObjectDeletedError(sa.exc.InvalidRequestError):
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"""An refresh() operation failed to re-retrieve an object's row."""
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class UnmappedColumnError(sa.exc.InvalidRequestError):
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"""Mapping operation was requested on an unknown column."""
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class NoResultFound(sa.exc.InvalidRequestError):
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"""A database result was required but none was found."""
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class MultipleResultsFound(sa.exc.InvalidRequestError):
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"""A single database result was required but more than one were found."""
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# Legacy compat until 0.6.
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sa.exc.ConcurrentModificationError = ConcurrentModificationError
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sa.exc.FlushError = FlushError
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sa.exc.UnmappedColumnError
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def _safe_cls_name(cls):
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try:
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cls_name = '.'.join((cls.__module__, cls.__name__))
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except AttributeError:
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cls_name = getattr(cls, '__name__', None)
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if cls_name is None:
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cls_name = repr(cls)
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return cls_name
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def _default_unmapped(cls):
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try:
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mappers = sa.orm.attributes.manager_of_class(cls).mappers
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except NO_STATE:
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mappers = {}
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except TypeError:
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mappers = {}
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name = _safe_cls_name(cls)
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if not mappers:
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return "Class '%s' is not mapped" % name
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