Question

在我的Firebase数据库中，父数据是所有用户的userId。他们每个人都有一个child("friends")，其中包含他们所有朋友的userId的列表。

我想获得每个currentUser的朋友userId并将currentUser的{{1}}添加到他们每个朋友的userId节点

这是我的数据结构的样子：

child("closeFriends")

我希望'closeFriends'是具有users 10XeC8j6OCcFTKj8Dm7lR7dVnkf1 email: "Dummy19@gmail.com" fcmToken: "cBW9XhpYqio:APA91bF6K5YgRj0PgyDCoApNpIWGO4icwFg..." friends ekFjYJU8OWTbYnQXVzhcxVE0wBP2: true profileImageUrl: "https://firebasestorage.googleapis.com/v0/b/jar..." username: "Dummy19" ePt3MSOuk6ZYDfekewmPlG4LgcU2 email: "Dummy20@gmail.com" fcmToken: "cBW9XhpYqio:APA91bF6K5YgRj0PgyDCoApNpIWGO4icwFg..." friends ekFjYJU8OWTbYnQXVzhcxVE0wBP2: true u43NtDYmqeTxafmLYjxxt60ngUo1: true profileImageUrl: "https://firebasestorage.googleapis.com/v0/b/jar..." username: "Dummy20" ekFjYJU8OWTbYnQXVzhcxVE0wBP2 email: "Dummy18@gmail.com" fcmToken: "cF-b_Fd8Ufc:APA91bG9bir1o_jdJdfB35l9g9HlNNTNHPM..." friends 10XeC8j6OCcFTKj8Dm7lR7dVnkf1: true ePt3MSOuk6ZYDfekewmPlG4LgcU2: true profileImageUrl: "https://firebasestorage.googleapis.com/v0/b/jar..." username: "Dummy18" u43NtDYmqeTxafmLYjxxt60ngUo1 email: "Dummy21@gmail.com" fcmToken: "cBW9XhpYqio:APA91bF6K5YgRj0PgyDCoApNpIWGO4icwFg..." friends ePt3MSOuk6ZYDfekewmPlG4LgcU2: true profileImageUrl: "https://firebasestorage.googleapis.com/v0/b/jar..." username: "Dummy21"的节点，就像userId一样。

这些是我的参考变量和函数：

friends

我尝试了这个let userReference = Database.database().reference().child("users") var currentUserReference: DatabaseReference { let id = Auth.auth().currentUser!.uid return userReference.child("\(id)") } var currentUserFriendsReference: DatabaseReference { return currentUserReference.child("friends") } var currentUserCloseFriendsReference: DatabaseReference { return currentUserReference.child("closeFriends") } var currentUserId: String { let uid = Auth.auth().currentUser!.uid return uid } func getCurrentUser(_ completion: @escaping (User) -> Void) { currentUserReference.observeSingleEvent(of: DataEventType.value) { (snapshot) in let email: String = snapshot.childSnapshot(forPath: "email").value as! String let uid = snapshot.key let username = snapshot.childSnapshot(forPath: "username").value as! String let profileImageUrl = snapshot.childSnapshot(forPath: "profileImageUrl").value as! String completion(User(uid: uid, userUsername: username, userProfileImageUrl: profileImageUrl, userEmail: email)) } } func getUser(_ userId: String, completion: @escaping (User) -> Void) { userReference.child(userId).observeSingleEvent(of: DataEventType.value, with: { (snapshot) in let email = snapshot.childSnapshot(forPath: "email").value as! String let uid = snapshot.key // Did the same thing here as in the above function let username = snapshot.childSnapshot(forPath: "username").value as! String let profileImageUrl = snapshot.childSnapshot(forPath: "profileImageUrl").value as! String completion(User(uid: uid, userUsername: username, userProfileImageUrl: profileImageUrl, userEmail: email)) }) } var closeFriendList = [User]()循环，但没有执行任何操作：

for

作为参考，func addCurrentUserToCloseFriendsLists(_ userId: String){ for friend in friendList{ let id = friend.uid self.getUser(id) { (user) in self.closeFriendList.append(user) self.userReference.child(userId).child("closeFriends").child(self.currentUserId).setValue(true) } }是在另一个文件（我的“ FriendSystem”）中创建的朋友的列表。

我确定还有另一种方法来获取所有用户的朋友，然后运行循环以将friendList添加到所有这些朋友的currentUser中，我只是无法弄清楚

超级固守于此，希望您能为您提供帮助！谢谢！

Answer 1

我想获取每个currentUser的朋友的userId并添加 currentUser的每个朋友子级的userId（“ closeFriends”）节点

让我们从一个与您相似的简单用户结构开始：

users
   uid_0
      name: "Larry"
      friends:
         uid_1: true
         uid_2: true
   uid_1
       name: "Moe"
   uid_2
       name: "Curly"

这个想法是浏览这个用户（当前用户）的朋友列表，并将这个用户的uid添加到其他用户的朋友列表中。在此示例中，我只是为每个用户创建一个“朋友”节点，但您可以将其设为“ closeFriends”或您想要的任何名称。

这是执行此操作的代码

let thisUserId = "uid_0"
func addThisUserIdToFriendsNode() {
    let usersRef = self.ref.child("users") //the general users node
    let thisUserRef = usersRef.child(self.thisUserId) //this users node
    let thisUserFriends = thisUserRef.child("friends") //this users list of friends

    //load in all of this users friends
    thisUserFriends.observeSingleEvent(of: .value, with: { snapshot in
        let allOfThisUsersFriends = snapshot.children.allObjects as! [DataSnapshot]
        for user in allOfThisUsersFriends {
            let friendRef = usersRef.child(user.key) //the friend ref
            let friendsFriendRef = friendRef.child("friends") //a friend friends child node
            let nodeToAdd = friendsFriendRef.child(self.thisUserId) //add this uid
            nodeToAdd.setValue(true)
        }
    })
}

和结果

users
   uid_0
      name: "Larry"
      friends:
         uid_1: true
         uid_2: true
   uid_1
       name: "Moe"
       friends
          uid_0: true
   uid_2
       name: "Curly"
       friends
          uid_0: true

Answer 2

我想，如果我对您的问题理解正确，那么您可以尝试使用Cloud DataStore代替RealtimeDB。您可以在here中找到此数据库之间的差异描述。

另一种方法-使用Firebase函数。

我想使用currentUser的userId并将其作为孩子添加到他们所有朋友的数据中-使用Swift在Firebase中

2 个答案: