iphone - coreData 实体实例创建失败，使用了多对多关系。RoomOccupant 创建失败？

Question

桌子

RoomOccupant < occupantid,relations(room,contact)>

因此，房间和联系人是 coreData 中的实体。从房间和联系人到 RoomOccupant 有一对多的关系。我已经定义了 addvalue、removevalue、addobjects 等，以正确添加 roomoccupant 关系。

因此，在创建 roomoccupant 时，我正在设置房间和居住者的联系方式。

occupant.room = room1, occupant.contact = contact1，因此 room1 和 contact1 是在 coreData 中创建的。

但它在“occupant.contact = contact1”声明中崩溃。如果解决了将不胜感激。提前致谢。

代码：

-(BOOL) setChatRoomOccupant:(RoomOccupant*)occupant
{
    CDChatRoomOccupants* occupantExisted = [self getChatRoomOccupant:occupant.occupantid];
    CDObjectFactory* factory = [[MobileClient getMobileClient] getFactory];
    if (!occupantExisted) 
    {
        CDChatRoom* room = [self setChatRoom:occupant.room];
        CDContact* contact = [factory setContact:occupant.contact];

        CDChatRoomOccupants* newOccupant = [NSEntityDescription insertNewObjectForEntityForName:@"CDChatRoomOccupants" inManagedObjectContext:localContext];
        newOccupant.occupantid = occupant.occupantid;
        if (contact) {
            NSLog(@"contact details:%@,%@",contact.phoneNumber,contact.firstName);
            newOccupant.contact = contact;
        }
        if (room) {
            newOccupant.room = room;
        }
        NSError* error = nil;
        if (![localContext save:&error]) {
            return true;
        }
    }
    else{
        occupantExisted.occupantid = occupant.occupantid;
        occupantExisted.room = [self setChatRoom:occupant.room];
        occupantExisted.contact = [factory setContact:occupant.contact];
        NSError* error = nil;
        if (![localContext save:&error]) {
            return true;
        }
    }
    return false;
}