Question

我已经环顾了一会儿，没有运气。我需要在firebase中获取某个字典键的字符串值。

如果您查看下面的图片，我需要在顶部设置该密钥，并且需要将其设置为等于字符串，我可以将其转移到其他视图控制器，以便当用户想要在共享者下发帖时，例如，我根据密钥进入正确的值，然后分享到我可以添加值的共享者。谢谢，我也不需要所有的值，只要我观察过单个事件，我需要获取每个页面或字典的密钥。

我的代码：

    let ref = FIRDatabase.database().reference()
    ref.child("Notes").queryOrderedByKey().observeSingleEvent(of: .value, with: { snapshot in
        if let pagers = snapshot.value as? [String : AnyObject] {
           let numb = snapshot.key //what I want
            for (_, val) in pagers {
                if let useri = val["postUsername"] as? String {
                    if useri == FIRAuth.auth()?.currentUser?.uid {

                        let bindfl = Page()
                        if let title = val["title"] as? String, let descript = val["description"] as? String,
                            let sharers = val["sharers"] as? [String], let poster = val["postUsername"] as? String, let setter = val["setter"] as? String, let creatorName = val["creatorName"] as? String {
                            bindfl.title = title
                            bindfl.descriptions = descript
                            bindfl.setter = setter
                            bindfl.sharers = sharers
                            bindfl.usernameOfBinder = poster
                            bindfl.creatorName = creatorName
                            bindfl.theBit = numb

                            self.pages.append(bindfl)

Answer 1

当你向数据库添加数据时，你可以这样做吗

let key = ref.("Notes").childByAutoId().key
let notes = ["userName": userName,
            "description": description,
            "title": title,
            "author": author,
            "keyID": key]
let childUpdates = ["/Notes/\(key)": notes]
ref.updateChildValues(childUpdates)

之后你就可以得到像这样的钥匙

bindfl.title = title
bindfl.descriptions = descriptions
bindfl.userName = userName
bindfl.author= author
bindfl.keyID= keyID

希望它有效。

Answer 2

ref.child("Notes"). observeSingleEvent(of: .childAdded, with: {snapshot in
   print("\(snapshot.key)")
})

将为您提供表格中每个条目的自动ID键

ref.child("Notes").queryOrdered(byChild: "creatorName").queryEqual(toValue: "posterName").observeSingleEvent(of: .childAdded, with: {snapshot in
     var postID = snapshot.key

  //update post different post using retrieved ID
     let infoToAdd = ["newPostStuff" : true]
     FIREBASE_REF!.child("Posts/\(postID)").updateChildValues(infoToAdd)
})

将为您提供给定创建者的每个帖子的自动ID，然后使用检索到的密钥更新不同表格上的值

如何检索某些childByAutoId（）键

2 个答案: