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这是一个fetchrequest的NSDictionnary结果:不明物体从核心数据检索
{
"appelation_vin" = Bordeaux;
"id_dom" = 134;
"vin_domaine" = "0x5b33ce0 <x-coredata://41A4D74E-EF4D-41DA-96F9-7F15DAE46403/domaine/p134>";
},
这里的奥秘,vin_domaine是supposely beetween两个表的关系的值,所以我知道对象键入它那假设至是(酒庄),但我不明白为什么它不是由CORE_DATA鉴定...
这里是有很大帮助的请求
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的帮助!