Question

我正在尝试在将用户UID存储到Cloud Firestore的文档引用中引用一个变量。路径似乎没有读取字符串。我尝试了两种不同的方式，两种方式都给我带来错误。您如何将变量字符串传递到Cloud Firestore文档/集合路径？

我从数据库中获得用户名ID：

UsernameID = Auth.auth().currentUser!.uid

var UsernameID = String()

let ref = db.collection("user/\(UsernameID)/account").document("created")
        ref.getDocument { (document, error) in
            if let document = document, document.exists {
                print("User Exists")
            } else {
                print("User does not exist in firestore")
            }
        }

抛出错误：

*** Terminating app due to uncaught exception 'FIRInvalidArgumentException', reason: 'Invalid path (user//account). Paths must not contain // in them.'
libc++abi.dylib: terminating with uncaught exception of type NSException

var UsernameID = String()

let ref = db.collection("user").document(UsernameID).collection("account").document("created")
        ref.getDocument { (document, error) in
            if let document = document, document.exists {
                print("User Exists")
            } else {
                print("User does not exist in firestore")
            }
        }

抛出错误：

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'FIRESTORE INTERNAL ASSERTION FAILED: Invalid document reference. Document references must have an even number of segments, but user has 1'

我也曾尝试将uid存储为DocumentReferce，但未能将字符串存储为DocumentReference。

let UsernameID = DocumentReference!

Answer 1

假设您正确进行身份验证，这是您要访问存储在Firestore中的文档的操作。假设结构是

users //collection
   uid //document
      name //field within the document

和用于读取名称字段的代码

let uid = Auth.auth().currentUser?.uid
let collectionRef = self.db.collection("users")
let userDoc = collectionRef.document(uid)
userDoc.getDocument(completion: { document, error in
     if let err = error {
         print(err.localizedDescription) //document did not exist
         return
     }

     if let doc = document {
         let name = doc.get("name")
         print(name)
     }
 })

Answer 2

在您的最佳示例中

db.collection("user/\(UsernameID)/account")

似乎您不是在请求用户集合。这就是为什么在集合名称中出现有关\的错误的原因。用户集合应该是这样的

let ref = db.collection("user").document(UsernameID)
        ref.getDocument { (document, error) in
            if let document = document, document.exists {
                print("User Exists")
            } else {
                print("User does not exist in firestore")
            }
        }

.document应该获取与传递的UsernameID相对应的用户文档。要获得属性，您需要通过document变量进行访问。

将变量传递到Firestore文档路径

2 个答案: