PROSAGA码农传奇-数据融合-Firebase数据库数据聚合

<div class =“post-text”itemprop =“text”>
  
    您应该实现“浅”树结构，并在需要时使用引用。
这意味着对于您应用中的大多数情况，您应该按原样使用该对象，确保它包含“基本数据”（在“聊天标题”下面的示例中），以及“更多”信息的键（在例如，“成员”的键。
  
  
    来自firebase docs（
    <a href="https://firebase.google.com/docs/database/web/structure-data" rel="nofollow noreferrer">
      https://firebase.google.com/docs/database/web/structure-data
    </A>
    ）：
  
  
    的
      坏
    </强>
  
   <pre>
 <code>
 {
 // 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": { ... }
 }
}

</code>
 </pre>
  
    的
      好
    </强>
  
   <pre>
 <code>
 {
 // 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": { ... }
  }
}

</code>
 </pre>
</DIV>