在将更多对象提取到实体后,核心数据关系丢失 [英] Core data relationship lost after fetching more objects into the entities
问题描述
我有一个类似这样的核心数据模型。
I have a core data model that looks like this.
在表格内载入我的所有约会。在自定义单元格里面的
UILabel
我设置约会位置名称如下。
Inside a tableview I load up all my appointments. On a UILabel
inside my custom cell
I set the appointments location name as follows.
NSString *info = appointment.location.label_vrij;
起初,所有的东西都可以工作,但是当我加载更多约会到我的数据库
。
所有信息字符串变为 NULL
。经过一些调试,我注意到 appointment.location
返回 NULL
。
At first everything works Oké, but when I load more appointments into my database
.
All the info strings goes NULL
. After some debugging I noticed that also appointment.location
returns NULL
.
这是我的NSFetchRequest看起来像
This is how my NSFetchRequest looks like
RKManagedObjectStore *store = [[SanMaxDataModel sharedDataModel] objectStore];
NSManagedObjectContext *context = store.mainQueueManagedObjectContext;
NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"Appointment"];
NSString *relationshipKeyPath = @"location"; // Set this to the name of the relationship on "A" that points to the "B" objects;
NSArray *keyPaths = [NSArray arrayWithObject:relationshipKeyPath];
[fetchRequest setRelationshipKeyPathsForPrefetching:keyPaths];
NSSortDescriptor *descriptor = [NSSortDescriptor sortDescriptorWithKey:@"dateStart" ascending:YES];
fetchRequest.sortDescriptors = @[descriptor];
NSPredicate *predicate = [NSPredicate predicateWithFormat:
@"tijd_dag = %@",strDate];
[fetchRequest setPredicate:predicate];
NSArray *matches = [context executeFetchRequest:fetchRequest error:nil];
appointments = [matches mutableCopy];
所以我认为我的关系只是乱七八糟?
So I think my relationship is just messed up ?
EDIT
我正在使用Restkit将我的约会映射到我的核心数据库。从下面的评论中,我决定关闭在Appointment实体内的location属性的选项标志。因为约会应该总是有位置。
I'm using Restkit for mapping my appointments into my core database. From the comments below I decided to turn off the option flag off the location attribute inside the Appointment entity. Because an appointment should always have a location.
现在,当我加载第一天。一切工程oké。但是当我尝试加载第二天,我得到错误:操作couldn\U2019t完成。 (Cocoa错误1570)
现在,当我看一看详细的错误
Now when I load up the first day. Everything works oké. But when i try to load up the next day , I get the error: The operation couldn\U2019t be completed. (Cocoa error 1570.)
Now when I take a look at the detailed Error
DetailedError: {
NSLocalizedDescription = "The operation couldn\U2019t be completed. (Cocoa error 1570.)";
NSValidationErrorKey = location;
NSValidationErrorObject = "<Appointment: 0x864e2f0> (entity: Appointment; id: 0x9272c70 <x-coredata://9692683D-3077-4362-9253-652AC5B36444/Appointment/p9> ; data: {\n autouur = 1;\n breekuur = 0;\n data1 = \"\";\n data2 = \"\";\n data3 = \"\";\n data4 = \"\";\n data5 = \"\";\n data6 = \"\";\n data7 = \"\";\n data8 = \"\";\n data9 = \"\";\n dateStart = \"2013-10-23 09:00:00 +0000\";\n dateStop = \"2013-10-23 09:30:00 +0000\";\n duration = 30;\n email = \"\";\n entryID = 774294984959;\n info = \"\";\n \"is_blocked\" = 0;\n \"is_except\" = 0;\n \"is_free\" = 1;\n \"is_moved\" = 0;\n \"is_vert\" = 0;\n locatieID = 773150;\n location = nil;\n multiID = nil;\n serverEntryID = 774294984959;\n serverLocatieID = 773150;\n sms = \"\";\n \"tijd_dag\" = 20131023;\n \"tijd_uur\" = 900;\n})";
}
这是我在核心数据中加载JSON的方式
This is how I load up the JSON in core data
-(void)getAppointmentsForDate:(NSString *)date forUserID:(NSString *)userID{
API *api = [API new];
RKManagedObjectStore *store = [[SanMaxDataModel sharedDataModel] objectStore];
NSLog(@"store is %@",store);
NSManagedObjectContext *context = store.mainQueueManagedObjectContext;
RKObjectManager *objectManager = [api mapAppointments];
NSString *urlString = [NSString stringWithFormat:@"/doctor/1.0/json/nl/appointments/get-by-date/apikey/%@?uid=%@&date=%@",APIKey,userID,date];
// NSString *urlString = [NSString stringWithFormat:@"/doctor/1.0/json/nl/appointments/get-by-date/apikey/%@?uid=77382&date=%@",APIKey,date];
NSURLRequest *request = [objectManager requestWithObject:nil method:RKRequestMethodGET path:urlString parameters:nil];
RKManagedObjectRequestOperation *operation = [objectManager managedObjectRequestOperationWithRequest:request managedObjectContext:context success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
NSLog(@"TILL HERE IN METHOD");
NSError *error = nil;
[[NSNotificationCenter defaultCenter] postNotificationName:@"appointmentsLoaded" object:self];
[[SanMaxDataModel sharedDataModel] saveToPersistentStoreAsync:&error];
} failure:^(RKObjectRequestOperation *operation, NSError *error) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error"
message:[error localizedDescription]
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil];
[alert show];
NSLog(@"Hit error: %@", error);
}];
[objectManager enqueueObjectRequestOperation:operation];
}
推荐答案
默认情况下RestKit会替换执行新映射时关系的内容。你需要告诉它,你想要与旧的新的关系数据。通过设置:
It looks like your problem is that by default RestKit replaces the contents of relationships when a new mapping is performed. You need to tell it that you want the new relationship data with the old. Do this by setting:
relationshipMapping.assignmentPolicy = RKAssignmentPolicyUnion;
如果您使用的是旧版本的RestKit,您需要使用 RKUnionAssignmentPolicy
。
If you're using an older version of RestKit you will need to use RKUnionAssignmentPolicy
.
其中 relationshipMapping
是 RKRelationshipMapping
实例。
Where relationshipMapping
is your RKRelationshipMapping
instance.
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