Firebase Firestore iOS 多种型号

Posted 2023-03-14

【中文标题】Firebase Firestore iOS 多种型号

【英文标题】：Firebase Firestore iOS Multiple Models

【发布时间】：2020-05-04 07:26:32

【问题描述】：

我是 Firestore 的新手，正在努力尝试在 ios 上找到具有几层的项目示例。我想利用 Firestore 提供的所有功能。

我有一个将测验映射到用户的用户设置。 （一切正常）现在我想建立我的测验结构。有问题的测验对象，这些问题有答案。

我已经将它构建到了一定的水平，但感觉很老套。谁能与我分享他们的最佳实践知识？这将不胜感激。

到目前为止的工作：

Firestore 格式：“/quizzes/idone/questions/idtwo/questions”

struct Quiz: Codable, Identifiable 
  @DocumentID var id: String?
  var title: String
  var score: Int?
  var completed: Bool
  @ServerTimestamp var createdTime: Timestamp?
  var userId: String?
  var questions: [Question]?

struct Question: Codable, Identifiable 
  @DocumentID var id: String?
  var title: String?
  var completed: Bool?
  //TODO: Answers

    do 
      var userQuiz = quiz
      userQuiz.userId = self.userId
        let questionOne = Question(title: "What day is it today?",
                                 imageName: "test.jpeg",
                                 completed: false)
        let questioTwo = Question(title: "What is the meaning of life?",
                                 imageName: "test.jpeg",
                                 completed: false)
      let _ = try db
            .collection("quizzes").addDocument(from: userQuiz) // Works perfect
            .collection("questions").addDocument(from: questionOne) // Here is the issue I can't add multiple questions.
    
    catch 
      fatalError("Unable to encode quiz: \(error.localizedDescription).")
    

  private func loadData() 
    if listenerRegistration != nil 
      listenerRegistration?.remove()
    
    listenerRegistration = db.collection(quizzesPath)
      .whereField("userId", isEqualTo: self.userId)
      .order(by: "createdTime")
      .addSnapshotListener  (querySnapshot, error) in
        if let querySnapshot = querySnapshot 
          self.quizzes = querySnapshot.documents.compactMap  document -> Quiz? in
            try? document.data(as: Quiz.self)
          
          //Todo: This is the main part I have a issue at. How do I consume my questions and mapp them to quizzes
          let questions = querySnapshot.documents.compactMap  document -> [Question]? in
            try? document.data(as: [Question].self)
          
          //self.quizzes.questions = questions
        
      
  

【参考方案1】：

如果您想了解数据模型的最佳实践以及如何构建数据，请查看这两个链接 [1] [2]。它还有一些视频，可以帮助您开始使用 Firestore。

[1]https://firebase.google.com/docs/firestore/data-model

[2]https://firebase.google.com/docs/firestore/manage-data/structure-data