iOS核心数据轻量级数据迁移示例？

Question

苹果提供的doc的轻量级迁移，这里是xcode4之前的好sample。

看起来像xcode4有点不同。

感谢有关xcode4中简单示例的任何线索，以说明核心数据的数据迁移。

Answer 1

只要注意添加选项的NSDictionary和NSPersistentStoreCoordinator初始化现在有选项参数设置从零到选项

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator 
{ 
    if (__persistentStoreCoordinator != nil) 
    { 
     return __persistentStoreCoordinator; 
    } 

    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"TradiesDB.sqlite"]; 

    NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys: 
          [NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, 
          [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil]; 

    NSError *error = nil; 
    __persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]]; 
    if (![__persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:options error:&error]) 
    { 
     /* 
      ... 
     */ 
     NSLog(@"Unresolved error %@, %@", error, [error userInfo]); 
     abort(); 
    }  

    return __persistentStoreCoordinator; 
}