Question

我正在尝试从Firestore数据库中的集合中检索数据。但是在打印检索到的数据时，它与我期望的格式不符。

这是我的代码，用于检索以下数据：

 let db = Firestore.firestore()

    func loadEvents() -> [Event] {
        var events = [Event]()
        let decoder = JSONDecoder()
        db.collection("Events").addSnapshotListener { QuerySnapshot, error in
            guard let documents = QuerySnapshot?.documents else {
                print("Error fetching documents: \(error!)")
                return
            }

            for doc in documents {
                let dict = doc.data()
                if let data = try? JSONSerialization.data(withJSONObject: dict, options: []) {
                    let event = try? decoder.decode(Event.self, from: data)
                    events.append(event!)
                    print(events) // Prints stuff like [Envy.Event] ...
                }
            }
//            let events = documents.map {$0.data()}
            }
        return events
    }

到达print(events)时，它会打印出[Envy.Event] [Envy.Event, Envy.Event] [Envy.Event, Envy.Event, Envy.Event] [Envy.Event, Envy.Event, Envy.Event, Envy.Event]之类的内容，该数据不适合用于操纵。我什至不了解这种格式；有人可以帮我吗？

Answer 1

您打印错误。您正在打印创建的整个模型类，则需要引用该类中的对象，例如。

print(events.name) // use the object name you have in your class
print(events.location) // use the object name you have in your class

要将数据添加到数组中示例代码：

db.collection("Events").getDocuments() { (querySnapshot, err) in
            if let err = err {
                print("Error getting documents: \(err)")
            } else {
                for document in querySnapshot!.documents {
                    let list = Event(name: document.get("yourKeyName") as? String,location: document.get("yourAnotherKeyName") as? String)

                    events.append(list)
                    print(event.name)
                    print(event.location)

                }
            }
        }

希望这会有所帮助

从Firestore数据库检索数据时出现问题

1 个答案: