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所以我迷失在這一個。我正在嘗試使用謂詞獲取父對象的子對象。如果我取出謂詞線,它會返回所有特定的帖子。所以我非常肯定它與謂詞有關的一個問題。任何幫助將不勝感激!以下是我的設置。iOS NSPredicate通過父實體過濾核心數據
AccountTimeLine - > SpecificPosts(一對多)
核心數據模型:
讀取的結果控制器:
- (void)specificPostFetch
{
DataAccessLayer *delegate = [[DataAccessLayer alloc]init];
self.managedObjectContext = delegate.managedObjectContext;
NSString *entityName = @"SpecificPosts";
NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:entityName];
request.sortDescriptors = [NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"createdDateSort" ascending:YES]];
request.predicate = [NSPredicate predicateWithFormat:@"accountTimeLine = %@", self.accountTimeLineObject];
[request setFetchBatchSize:20];
self.specificPostFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
self.specificPostFetchedResultsController.delegate = self;
[self.specificPostFetchedResultsController performFetch:nil];
}
打印出是accountTimeLineObject的用於比較謂詞
po self.accountTimeLineObject
<AccountTimeLine: 0x7c087b70> (entity: AccountTimeLine; id: 0x7c086590 <x-coredata://353F201D-E739-4DD0-BEBF-DAD6101CFE51/AccountTimeLine/p72> ; data: {
accountType = 0;
nextPageUrl = 515986477864337411;
sort = 0;
specificPosts = "<relationship fault: 0x7c634590 'specificPosts'>";
userAccountId = 582;
})
是啊,我嘗試過這一點。不會改變任何東西。不確定這些謂詞中是否存在==和=之間的差異?我也嘗試添加ObjectId像這樣「request.predicate = [NSPredicate predicateWithFormat:@」accountTimeLine ==%@「,[self.accountTimeLineObject objectID]];」那也沒用。任何其他想法? – mikemike396 2014-09-28 00:15:49
你有錯誤,或者只是一個空數組? – pbasdf 2014-09-28 00:19:06
當我在cellForRow上放置一個斷點時,空結果控制器。當我註釋謂詞行時,我返回了40個對象。 (lldb)po [self.specificPostFetchedResultsController.fetchedObjects count]; –
mikemike396
2014-09-28 00:21:02