Core data 无法与NSPersistentDocument和Core数据一起保存

我很难看到这个（null）实体涉及到了哪里。我已经检查了所有的绑定设置，CoreData模型，检查了文档等等。不知道。 控制台即将出现：

2013-10-10 19:41:44.666 BusinessDesk[17180:303]无法执行操作，因为找不到名为“（null）”的实体

2013-10-10 19:41:44.673商务台[17180:303](

)

---

有人对此有点了解吗？

你在应用程序的生命周期中处于什么位置？我已经看过几次了，发现我忘记在某个地方设置实体名称，但问题通常出现在保存之前。这是一个现有的数据库还是一个您正在尝试创建的新数据库，使用sqlite、xml或二进制、iCloud打开或关闭？当我尝试保存它时会发生这种情况。我使用的是NSPersistentDocument，因此该类的默认设置将用于数据。不使用iCloud。我已经把它缩小到一个表列的绑定，但它仍然很奇怪。如果我取消选择绑定，它会保存好。然后我打开一个新文档，问题又出现了。需要更仔细地研究这个绑定。就我所见，所有实体似乎都被正确命名。当它试图保存时，我试图将其保存为二进制（似乎是默认值）。我也有同样的问题，也没有任何想法。你同时解决了这个问题吗？

0   CoreFoundation                      0x00007fff8db8741c __exceptionPreprocess + 172
1   libobjc.A.dylib                     0x00007fff930d6e75 objc_exception_throw + 43
2   CoreFoundation                      0x00007fff8db872cc +[NSException raise:format:] + 204
3   AppKit                              0x00007fff93b0c3a8 -[_NSManagedProxy _entity] + 141
4   AppKit                              0x00007fff93b0c265 -[_NSManagedProxy fetchRequestWithSortDescriptors:limit:] + 95
5   AppKit                              0x00007fff93d5c40a -[_NSManagedProxy _storesDidChange:] + 125
6   CoreFoundation                      0x00007fff8db55fcc __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 12
7   CoreFoundation                      0x00007fff8da49c5d _CFXNotificationPost + 2893
8   Foundation                          0x00007fff948994aa -[NSNotificationCenter postNotificationName:object:userInfo:] + 68
9   CoreData                            0x00007fff926aa6ad -[NSPersistentStoreCoordinator(_NSInternalMethods) _postStoresChangedNotificationsForStores:changeKey:options:] + 253
10  CoreData                            0x00007fff9269aea6 -[NSPersistentStoreCoordinator addPersistentStoreWithType:configuration:URL:options:error:] + 2342
11  AppKit                              0x00007fff93d7a549 -[NSPersistentDocument configurePersistentStoreCoordinatorForURL:ofType:modelConfiguration:storeOptions:error:] + 1268
12  AppKit                              0x00007fff940209a1 -[NSPersistentDocument(NSDeprecatedInternal) _configurePersistentStoreCoordinatorForURL:ofType:error:] + 156
13  AppKit                              0x00007fff93d7ad1c -[NSPersistentDocument writeToURL:ofType:forSaveOperation:originalContentsURL:error:] + 818
14  AppKit                              0x00007fff93c11a2f -[NSDocument _writeSafelyToURL:ofType:forSaveOperation:forceTemporaryDirectory:error:] + 339
15  AppKit                              0x00007fff93c1259c -[NSDocument _writeSafelyToURL:ofType:forSaveOperation:error:] + 28
16  AppKit                              0x00007fff93c12709 -[NSDocument writeSafelyToURL:ofType:forSaveOperation:error:] + 356
17  AppKit                              0x00007fff93d7c283 -[NSPersistentDocument writeSafelyToURL:ofType:forSaveOperation:error:] + 601
18  AppKit                              0x00007fff93c1d58c __66-[NSDocument saveToURL:ofType:forSaveOperation:completionHandler:]_block_invoke_22042 + 76
19  AppKit                              0x00007fff93c1e877 __66-[NSDocument saveToURL:ofType:forSaveOperation:completionHandler:]_block_invoke_22125 + 248
20  AppKit                              0x00007fff93c1e770 __66-[NSDocument saveToURL:ofType:forSaveOperation:completionHandler:]_block_invoke2122 + 341
21  AppKit                              0x00007fff93c1d480 __66-[NSDocument saveToURL:ofType:forSaveOperation:completionHandler:]_block_invoke2033 + 1501
22  Foundation                          0x00007fff949449f9 -[NSFileCoordinator(NSPrivate) _invokeAccessor:orDont:thenRelinquishAccessClaimForID:] + 224
23  Foundation                          0x00007fff94ab7637 -[NSFileCoordinator(NSPrivate) _coordinateWritingItemAtURL:options:error:byAccessor:] + 702
24  AppKit                              0x00007fff93c1915f -[NSDocument _fileCoordinator:coordinateReadingContentsAndWritingItemAtURL:byAccessor:] + 421
25  AppKit                              0x00007fff93c1c7a4 __66-[NSDocument saveToURL:ofType:forSaveOperation:completionHandler:]_block_invoke + 599
26  AppKit                              0x00007fff93c0a595 -[NSDocument continueFileAccessUsingBlock:] + 234
27  AppKit                              0x00007fff93c0aa2d -[NSDocument _performFileAccessOnMainThread:usingBlock:] + 782
28  AppKit                              0x00007fff93c0b6b4 -[NSDocument performAsynchronousFileAccessUsingBlock:] + 481
29  AppKit                              0x00007fff93c1c53e -[NSDocument saveToURL:ofType:forSaveOperation:completionHandler:] + 148
30  AppKit                              0x00007fff93c1895f __85-[NSDocument saveToURL:ofType:forSaveOperation:delegate:didSaveSelector:contextInfo:]_block_invoke_2 + 310
31  AppKit                              0x00007fff93c45910 -[NSDocument _commitEditingThenContinue:] + 501
32  AppKit                              0x00007fff93d79661 __62-[NSPersistentDocument _documentEditor:didCommit:withContext:]_block_invoke + 53
33  CoreFoundation                      0x00007fff8dab87cc __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
34  CoreFoundation                      0x00007fff8daa9ee5 __CFRunLoopDoBlocks + 341
35  CoreFoundation                      0x00007fff8daa9c6e __CFRunLoopRun + 1982
36  CoreFoundation                      0x00007fff8daa9275 CFRunLoopRunSpecific + 309
37  HIToolbox                           0x00007fff8d722f0d RunCurrentEventLoopInMode + 226
38  HIToolbox                           0x00007fff8d722b85 ReceiveNextEventCommon + 173
39  HIToolbox                           0x00007fff8d722abc _BlockUntilNextEventMatchingListInModeWithFilter + 65
40  AppKit                              0x00007fff9379f28e _DPSNextEvent + 1434
41  AppKit                              0x00007fff9379e8db -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 122
42  AppKit                              0x00007fff937929cc -[NSApplication run] + 553
43  AppKit                              0x00007fff9377d803 NSApplicationMain + 940
44  BusinessDesk                        0x000000010000b3d2 main + 34
45  libdyld.dylib                       0x00007fff907fa5fd start + 1