swift firebase一对多例子？

Question

我已经创建了2个表格。我想选择表朋友，我想显示名称从表用户？任何人都可以帮助我例如迅速请谢谢。

表用户

id 
name 
email 

表的朋友

id 
user_id 
friend_id 

Answer 1

你的实时数据库应该是这个样子。

{ 
    "users": { 
     "1": { 
      "name": "John Doe", 
      "email": "john@example.com" 
     }, 
     "2": { 
      "name": "Jane Doe", 
      "email": "jane@example.com" 
     } 
    }, 
    "user-friends": { 
     "1": { 
      "2": true 
     }, 
     "2": { 
      "1": true 
     } 
    } 
} 

为了得到约翰的朋友，我们观察到的路径/user-friends/1

let uid = 1 // the uid of the user we want the friends of 
let ref = FIRDatabase.database().reference().child('user-friends/\(uid)') 

ref.observeEventType(.ChildAdded, block: { snapshot in 

    let uid = snapshot.key // the uid of a user who is John's friend 
    let ref = FIRDatabase.database().reference().child('users/\(uid)') 

    ref.observeSingleEventOfType(.Value, block: { snapshot in 
     if let json = snapshot.value as? [String:AnyObject] { 
      print(json["name"]) 
     } 
    }) 
})