swift - 从 Firestore 文档中获取单个元素

Question

如何从我的 Firebase 文档中获取单个项目？

我可以用这段代码获取所有元素:

 let key = UserDefaults.standard.value(forKey: "uid") as! String
        let docRef = firebaseDB.collection("user").document(key)

        docRef.getDocument { (document, error) in
            if let document = document, document.exists {
                let dataDescription = document.data().map(String.init(describing:))
                print("Document data: \(dataDescription)")

            } else {
                print("Document does not exist")
            }
        }

我只想知道姓名和电话号码。如何过滤我的结果？

Answer 1

FirebaseFirestore 有一种缓存单个文档的简便方法:

首先，您需要通过其 ID 指定文档:

let key = UserDefaults.standard.value(forKey: "uid") as? String ?? "Null" // Unique user key
let docRef = db.collection("user").document(key)

获取文档:

docRef.getDocument { (document, error) in
     if let document = document, document.exists {
         let docData = document.data()
         // Do something with doc data
      } else {
         print("Document does not exist")

      }
}

访问文档数据:

 let status = docData!["phone"] as? String ?? ""