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這是一個fetchrequest的NSDictionnary結果:不明物體從核心數據檢索
{
"appelation_vin" = Bordeaux;
"id_dom" = 134;
"vin_domaine" = "0x5b33ce0 <x-coredata://41A4D74E-EF4D-41DA-96F9-7F15DAE46403/domaine/p134>";
},
這裏的奧祕,vin_domaine是supposely beetween兩個表的關係的值,所以我知道對象鍵入它那假設至是(酒莊),但我不明白爲什麼它不是由CORE_DATA鑑定...
這裏是有很大幫助的請求
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
[fetchRequest setEntity:[NSEntityDescription entityForName:@"vin" inManagedObjectContext:managedObjectContext]];
[fetchRequest setReturnsObjectsAsFaults:NO];
[fetchRequest setResultType:NSDictionaryResultType];
[fetchRequest setReturnsDistinctResults:YES];
[fetchRequest setPropertiesToFetch:[NSArray arrayWithObjects:@"appelation_vin",@"id_dom",@"vin_domaine",nil]];
NSString *mysearch= [NSString stringWithFormat:@"appelation_vin= '%@'",appelation];
NSPredicate *predicate = [NSPredicate predicateWithFormat:mysearch,10];
[fetchRequest setPredicate:predicate];
[fetchRequest setRelationshipKeyPathsForPrefetching:[NSArray arrayWithObject:@"domaine"]];
THX的幫助!