如何生成 JSON 文件以预加载和导入 coreData？

Question

我正在关注 raywenderlich.com 上的热门教程来预加载核心数据。 这是我的 JSON 文件：

[
{
    "countDescription": "###",
    "countId": "###",
    "states": [
        {
            "stateDesc": "###",
            "stateId": "###",
            "cities": [
                {
                    "cityDescription": "###",
                    "cityId": "###",
                    "destinations": [
                        {
                            "destDescription": "###",
                            "destId": "###"
                        },
                        {
                            "destDescription": "###",
                            "destId": "###"
                        }
                    ]
                },
                {
                    "cityDescription": "###",
                    "cityId": "###",
                    "destinations": [
                        {
                            "destDescription": "###",
                            "destId": "###"
                        },
                        {
                            "destDescription": "###",
                            "destId": "###"
                        }
                    ]
                }
            ]
        },
        {
            "stateDesc": "###",
            "stateId": "###",
            "cities": [
                {
                    "cityDescription": "###",
                    "cityId": "###",
                    "destinations": [
                        {
                            "destDescription": "###",
                            "destId": "###"
                        },
                        {
                            "destDescription": "###",
                            "destId": "###"
                        }
                    ]
                }
            ]
        }
    ]
},
{
    "countDescription": "###",
    "countId": "###",
    "states": [
        {
            "stateDesc": "###",
            "stateId": "###",
            "cities": [
                {
                    "cityDescription": "###",
                    "cityId": "###",
                    "destinations": [
                        {
                            "destDescription": "###",
                            "destId": "###"
                        }
                    ]
                }
            ]
        }
    ]
}
]

我的问题是如何在 excel 中执行此操作，然后我可以将其保存为 CSV 文件并使用 converter 获取我的 JSON。

在转换器网站中，我使用了 JSON-to-CSV 选项，但生成的 CSV 文件只为我提供实体 Country 的列，然后每一行的其他所有内容都在下一列中，其他属性的名称消失。

如果我使用另一个 source 那就太好了，它看起来就像我想的那样：

    "countDescription","countId","states__stateDesc","states__stateId","states__cities__cityDescription","states__cities__cityId","states__cities__destinations__destDescription","states__cities__destinations__destId"
"###","###","###","###","###","###","###","###"
"","","","","","","###","###"
"","","","","###","###","###","###"
"","","","","","","###","###"
"","","###","###","###","###","###","###"
"","","","","","","###","###"
"###","###","###","###","###","###","###","###"

但是，一旦我对表格进行了更改，然后继续将其保存为 CSV 文件，格式就不同了，这是什么原因？

英语是我的第二语言，我希望我的问题不是太难理解，如果你们不介意我问，一对多对一对多对一是否正确-数据模型的多对多？我确实设法将 JSON 文件预加载到核心数据中。

Answer 1

我认为快速编写自己的解析器并解析 CSV 文件要容易得多。至少这是我的工作流程，并且被证明是非常有效的。以字符串的形式读入文件，分成除以\n的数组，循环遍历行，每行循环遍历字段，以列标题为键构造字典。

然后使用NSJSONSerialization 类方法生成您的JSON 数据（提示：使用.PrettyPrinted 选项以提高可读性）。然后，您可以使用 String(data:encoding:) 从数据中生成 String 并将其保存到文件中（或将其转储到控制台并复制粘贴）。