查询Firebase嵌套的子Swift [英] Query Firebase for nested child swift

问题描述

我需要帮助在Firebase中获取嵌套的数据。

以下是我的数据在Firebase中的结构：

   -  Meetups 
  -  UniqueID 
  - 地址：xxxx
  - 日期：xxxx
  - 创建者：xxxx
  -  inviteFriends 
  -  1：xxxx
  -  2：xxxx
  -  3：xxxx
  

我试图找出如何检索inviteFriends数据。

目前我用这种方式检索数据：

  BASE_URL.child（meetups）。observeEventType（.Value，withBlock：{snapshot in 
 
 self.meetups = [] 
 
 
如果让snapshots = snapshot.children.allObjects as？[FIRDataSnapshot] {
 
快照中的快照{
 
如果让postDictionary = snap.value as？Dictionary< String，AnyObject> {
 let key = snap.key 
 
 meetup = Meetup（key：key，dictionary： postDictionary）
 
 self.meetups.insert （meetup，atIndex：0）
 
} 
} 
  

这使我可以从地址，日期和创建者中创建我的Meetup类的实例。不过，我最近将inviteFriends数据添加到了结构中，并且试图找出如何在同一个进程中查询它。感谢您的任何建议！

解决方案

通过这种方式修改您的 for ： -

 如果让snapDict = snapshot.value为？ NSMutableDictionary {
 for snapDict（
 let user_ID = snap.key 
 Base 
 BASE_URL.child（meetups）。child（user_ID）.child（invitedFriends） .observeEventType（.Value，withBlock：{snapshot in $ b $ if if snapshot.exists（）{
 for snapshotsValue中的被邀请者{
 let inviteFrnds = invitees.Value 
 //检索朋友。
 //其余的代码
} 
} 
}）
} 
} 
  

I need help getting nested data in Firebase.

Here is how my data is structured in Firebase:

- Meetups
 - UniqueID
   - address: "xxxx"
   - date: "xxxx"
   - creator: "xxxx"
   - invitedFriends
      - 1: "xxxx"
      - 2: "xxxx"
      - 3: "xxxx"

I am trying to figure out how to retrieve the invitedFriends data.

Currently I retrieve the data this way:

BASE_URL.child("meetups").observeEventType(.Value, withBlock: { snapshot in

  self.meetups = []


  if let snapshots = snapshot.children.allObjects as? [FIRDataSnapshot] {

    for snap in snapshots {

      if let postDictionary = snap.value as? Dictionary<String, AnyObject> {
        let key = snap.key

        let meetup = Meetup(key: key, dictionary: postDictionary)

        self.meetups.insert(meetup, atIndex: 0)

      }
    }

This allows me to create an instance of my Meetup class from the address, date, and creator. However, I recently added the invitedFriends data to the structure and I am trying to figure out how to query it in this same process. Thank you for any suggestions!

解决方案

Modify your for loop this way:-

if let snapDict = snapshot.value as? NSMutableDictionary{
    for snap in snapDict{
       let user_ID = snap.key
       Base
     BASE_URL.child("meetups").child(user_ID).child("invitedFriends").observeEventType(.Value, withBlock: { snapshot in
     if snapshot.exists(){
         for invitees in snapshot.Value{
            let invitedFrnds = invitees.Value
            //Retrieving the friends.
            //Rest of your code accordingly
         }
      }
    })
  }
}

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