无法从Firebase检索数据库实例

问题描述

由于某些原因，我无法从Firebase数据库检索数据。请看看我的代码和规则。谢谢

我的代码

List<EvaluatingImage> imageInfo = [];

  Future<Query> queryUsers() async {
    // DatabaseReference referenceData =
    //     FirebaseDatabase.instance.reference().child('pictures');
    DatabaseReference referenceData =
        FirebaseDatabase.instance.reference().child('users');
    referenceData.once().then((DataSnapshot dataSnapShot) {
      Map<dynamic,dynamic> values = dataSnapShot.value;
      values.forEach(
        (key,value) {
          print(value['email']);
        },);
    });
  }

规则

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {

    // This rule allows anyone with your database reference to view,edit,// and delete all data in your Firestore database. It is useful for getting
    // started,but it is configured to expire after 30 days because it
    // leaves your app open to attackers. At that time,all client
    // requests to your Firestore database will be denied.
    //
    // Make sure to write security rules for your app before that time,or else
    // all client requests to your Firestore database will be denied until you Update
    // your rules
    match /{document=**} {
      //allow read,write: if request.time < timestamp.date(2020,9,28);
      allow read,write : if true;
    }
  }
}

相反，我收到此错误

W/SyncTree(29984): Listen at /users failed: DatabaseError: Permission denied
E/flutter (29984): [ERROR:flutter/lib/ui/ui_dart_state.cc(166)] Unhandled Exception: DatabaseError(-3,Permission denied,)
E/flutter (29984):

请帮助我！非常感谢您的帮助。

解决方法

以上规则适用于使用Firebase实时数据库的firestore，您需要将实时数据库的规则更改为以下内容：

{
  "rules": {
    ".read": true,".write": true
  }
}

注意：以上规则将使所有用户都可以从数据库读取和写入数据，仅使用上述规则进行开发

https://firebase.google.com/docs/database/security