Firebase数据库数据聚合

让我们以“类似Instagram”的应用程序为例

在feed中，我们得到了帖子，用户头像和名字在顶部，照片或视频在下面，最后的评论，喜欢计数和发布时间在底部

基本上，在客户端，我正在等待从后端获取类似

{
用户名：“John”，
阿凡达：“一些链接”，
照片：“照片url”，
喜欢：“9”，
时间：“182937428”，
评论：[那里的评论]
}

但是使用Firebase，我需要以更平坦的方式存储数据。因此，在数据JSON中会有“用户”、“帖子”和“评论”

我该如何将来自这些节点的数据聚合到某种单一对象中，这在客户端很容易使用

或者我应该要求Firebase提供帖子，而不是所有用户的帖子，以及他们的所有评论，并在完成所有三个“请求”后进行聚合吗

您应该实现“浅”树结构，并在需要时使用引用。 这意味着在应用程序中的大多数情况下，您应该按原样使用对象，确保它包含“基本数据”（在下面的示例中为“聊天标题”）和“进一步”信息的键（在示例中为“成员”的键）

从firebase文档（）：

坏的

{
  // This is a poorly nested data architecture, because iterating the children
  // of the "chats" node to get a list of conversation titles requires
  // potentially downloading hundreds of megabytes of messages
  "chats": {
    "one": {
      "title": "Historical Tech Pioneers",
      "messages": {
        "m1": { "sender": "ghopper", "message": "Relay malfunction found. Cause: moth." },
        "m2": { ... },
        // a very long list of messages
      }
    },
    "two": { ... }
  }
}

{
  // Chats contains only meta info about each conversation
  // stored under the chats's unique ID
  "chats": {
    "one": {
      "title": "Historical Tech Pioneers",
      "lastMessage": "ghopper: Relay malfunction found. Cause: moth.",
      "timestamp": 1459361875666
    },
    "two": { ... },
    "three": { ... }
  },

  // Conversation members are easily accessible
  // and stored by chat conversation ID
  "members": {
    // we'll talk about indices like this below
    "one": {
      "ghopper": true,
      "alovelace": true,
      "eclarke": true
    },
    "two": { ... },
    "three": { ... }
  },

  // Messages are separate from data we may want to iterate quickly
  // but still easily paginated and queried, and organized by chat
  // conversation ID
  "messages": {
    "one": {
      "m1": {
        "name": "eclarke",
        "message": "The relay seems to be malfunctioning.",
        "timestamp": 1459361875337
      },
      "m2": { ... },
      "m3": { ... }
    },
    "two": { ... },
    "three": { ... }
  }
}

好

{
  // This is a poorly nested data architecture, because iterating the children
  // of the "chats" node to get a list of conversation titles requires
  // potentially downloading hundreds of megabytes of messages
  "chats": {
    "one": {
      "title": "Historical Tech Pioneers",
      "messages": {
        "m1": { "sender": "ghopper", "message": "Relay malfunction found. Cause: moth." },
        "m2": { ... },
        // a very long list of messages
      }
    },
    "two": { ... }
  }
}

{
  // Chats contains only meta info about each conversation
  // stored under the chats's unique ID
  "chats": {
    "one": {
      "title": "Historical Tech Pioneers",
      "lastMessage": "ghopper: Relay malfunction found. Cause: moth.",
      "timestamp": 1459361875666
    },
    "two": { ... },
    "three": { ... }
  },

  // Conversation members are easily accessible
  // and stored by chat conversation ID
  "members": {
    // we'll talk about indices like this below
    "one": {
      "ghopper": true,
      "alovelace": true,
      "eclarke": true
    },
    "two": { ... },
    "three": { ... }
  },

  // Messages are separate from data we may want to iterate quickly
  // but still easily paginated and queried, and organized by chat
  // conversation ID
  "messages": {
    "one": {
      "m1": {
        "name": "eclarke",
        "message": "The relay seems to be malfunctioning.",
        "timestamp": 1459361875337
      },
      "m2": { ... },
      "m3": { ... }
    },
    "two": { ... },
    "three": { ... }
  }
}

---

我还是不明白。那么，如果我用“阿凡达”、“姓名”、“年龄”来表示“用户”呢。我得到了带有“url”、“count”和“userId”的“post”。如何把它组合起来？手动为每一个“帖子”创建一个“帖子”，并将“user.avatar”和“user.name”添加到客户端实现上的its中？如果有成千上万的帖子呢？？或者我应该将数据从用户复制到帖子？若用户更改了名称或头像呢？？？