如何改进我的 JSON 架构？

Question

我这里有这个JSON：

  [{
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ -2.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 1.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ -5.449212707644754, 2.3458776596, -1.452433 ]
  }]

表示图形中的点列表。在这种情况下，对于给定的时间戳，我们有三个点，因此 JSON 描述了三个图（三个通道）。

这适用于普通频道（即简单浮点值列表）。到目前为止一切顺利。

不幸的是，在某些情况下，我们有所谓的 "minmax" 通道，其中每个点都表示为一对浮点数！

让我们以最后一个例子为例，将中间通道（第二个）替换为 "minmax" 通道。这里的问题是我不知道如何 JSON-ize 那个 "minmax" 通道的一对浮点数而没有歧义。

  [{
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ -2.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 1.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ -5.449212707644754, ???, -1.452433 ]
  }]

最好的方法是什么？我可以在其他数组中包含未命名的数组吗？那么在 Javascript 对象中反序列化这样的 JSON 呢？

Answer 1

你可以在这部分嵌套一个数组，像这样：

没有极小极大值：

  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ [0.449212707644754], [1.11111], [1.452433] ]
  },

极小极大：

  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ [0.449212707644754], [1.11111, 1.63245345], [1.452433] ]
  },

然后在解析时，你只需要检查第二个通道有多少个数组元素，这样你就可以确定它是否是极小极大。当然，它与通道一和通道三完全一样。

When typed, an array is represented as open and closed brackets: []which may contain a comma-separated list of values[ "a", "b", "c" ]. These values can be any JSON data type: string, number,boolean, object, array, null. Source: https://www.json.com/json-array

Answer 2

如果频道有一定意义，您还可以考虑将以下架构替换为 first、second 和 third 名称以更好地描述频道。

{
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "Channels": {
        "first": {
            "value": -5.449212707644754
        },
        "second": {
            "min": 0.312,
            "max": 1.2312321
        },
        "third": {
            "value": -1.452433
        }
    }
}

该解决方案的优点是可读性更好。很明显 min 和 max 是什么意思。如果你使用嵌套数组，没有人会知道这是一个 "minmax" 频道

Answer 3

使您的频道值成为一个对象数组。这样您就可以命名这些对象的属性，而不是依赖它们的位置来指示它们的含义。例如

{
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [
        { 
            value: -2.449212707644754
        },
        { 
            min: -2.449212707644754,
            max: 4.678432425151,
        },
        { 
            value: 1.452433
        }
    ]
}

关于 JSON 数据大小，大多数 Web 服务器将允许您启用 HTTP 响应压缩，浏览器将自动解压缩。这在服务器端非常容易启用。压缩后的 JSON 与 Google Protocol Buffers 等二进制协议一样小。在这种情况下，JSON 中会有很多冗余，因此它应该非常好地压缩。您也可以将属性名称设为单个字符。例如v 为值，n 为最小值，x 为最大值。

{
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [
        { 
            v: -2.449212707644754
        },
        { 
            n: -2.449212707644754,
            x: 4.678432425151,
        },
        { 
            v: 1.452433
        }
    ]
}

如何改进我的 JSON 架构？

How can I improve my JSON schema?

javascript

serialization

json

json-deserialization