Question

通过JSON填充一对多核心数据模型时遇到问题。

背景：

Two Entities:

    WorkoutType
    Attributes:
        -workoutType
    Relationship: workouts
    Destination: WorkoutSet
    Inverse: workoutType

    WorkoutSet
    Attributes:
        -workoutName
    Relationship: workoutType
    Destination: WorkoutType
    inverse: workouts

以下是我的JSON：

[
  { "workoutType": "Strength",
           "workouts":
            [   { "workoutName": "Strength 1"},
                { "workoutName": "Strength 2"},
                { "workoutName": "Strength 3"},
                { "workoutName": "Strength 4"}
                ],
  },
  { "workoutType": "Core",
           "workouts":
            [   { "workoutName": "Core 1"},
                { "workoutName": "Core 2"},
                { "workoutName": "Core 3"},
                { "workoutName": "Core 4"}
                ],
 }
]

JSON正确解析，问题是对于每个WorkoutType（核心和力量）应该有4个锻炼（强度1，力量2，......）..（核心1，核心2，.... ）。

在查看创建的sqlite数据库后，我实现的是，Strength有3次锻炼，Core有5次锻炼。每次编译代码时，数字都会改变。

我正在使用的代码如下：

    NSString* thirdDataPath = [[NSBundle mainBundle] pathForResource:@"Workouts" ofType:@"json"];
    NSArray* Workouts = [NSJSONSerialization JSONObjectWithData:[NSData dataWithContentsOfFile:thirdDataPath]
                                                       options:kNilOptions
                                                         error:&err];
    NSLog(@"Imported Workouts: %@", Workouts);

    [Workouts enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {

        WorkoutType *workoutType = [NSEntityDescription
                          insertNewObjectForEntityForName:@"WorkoutType"
                          inManagedObjectContext:context];
        workoutType.workoutType = [obj objectForKey:@"workoutType"];



        NSArray *workoutsArray = [obj objectForKey:@"workouts"];
        [workoutsArray enumerateObjectsUsingBlock:^(id workoutsObj, NSUInteger workoutsIdx, BOOL *workoutsStop) {


            WorkoutSet *workoutSet = [NSEntityDescription
                                      insertNewObjectForEntityForName:@"WorkoutSet"
                                      inManagedObjectContext:context];


            //Not Sure if the line below is correct, also not sure if i should be setting the relationship here too something like workoutSet.workouts = .... 
            workoutSet.workoutType = workoutType;
            workoutSet.workoutName = [workoutsObj objectForKey:@"workoutName"];
        }];

        NSError *error;
        if (![context save:&error]) {
            NSLog(@"Whoops, couldn't save: %@", [error localizedDescription]);
        }

    }];

请轻松，我是新手。在代码中我添加了评论，我认为我可能犯了错误。

将不胜感激任何帮助。谢谢。

将一对多关系JSON填充到核心数据

0 个答案: