Javascript 在运行嵌套查询的嵌套对象上使用firebase cloud函数搜索数据时未指定索引

我使用fire base检索用户节点的嵌套数据，在运行查询时，我遇到了从fire base数据库获取数据的问题

考虑在以下位置添加“.indexOn”：“userId” /users/YJdwgRO08nOmC5HdEokr1NqcATx1/following/users到您的安全 提高性能的规则

数据库结构：

 "users" : {
    "1vWvSXDQITMmKdUIY7SYoLA1MgU2" : {
      "userEmail" : "test2kawee@gmail.com",
      "userId" : "1vWvSXDQITMmKdUIY7SYoLA1MgU2",
      "userName" : "Malik Abdul Kawee",
      "userPhoneNumber" : "",
      "userProfileImage" : "https://pbs.twimg.com/profile_images/1018741325875867648/ZnKeUiOJ_400x400.jpg"
    },
    "YJdwgRO08nOmC5HdEokr1NqcATx1" : {
      "following" : {
        "1vWvSXDQITMmKdUIY7SYoLA1MgU2" : {
          "currentFollowingUserId" : "YJdwgRO08nOmC5HdEokr1NqcATx1",
          "userEmail" : "test2kawee@gmail.com",
          "userId" : "1vWvSXDQITMmKdUIY7SYoLA1MgU2",
          "userName" : "Malik Abdul Kawee",
          "userPhoneNumber" : "",
          "userProfileImage" : "https://pbs.twimg.com/profile_images/1018741325875867648/ZnKeUiOJ_400x400.jpg"
        }
      },
      "userEmail" : "test2atif@gmail.com",
      "userId" : "YJdwgRO08nOmC5HdEokr1NqcATx1",
      "userName" : "Atif AbbAsi",
      "userPassword" : "test123",
      "userPhoneNumber" : "",
      "userProfileImage" : "http://paperlief.com/images/enrique-iglesias-body-workout-wallpaper-4.jpg"
    }
  }

    "users": {
     ".indexOn":  ["userId","currentFollowingUserId",".value"],
       "$userId": {
         "following": {
        //"$userId": {
             ".indexOn":  ["userId","currentFollowingUserId",".value"]
        }
    //}
       } 
}

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);


exports.sendFollowingNotifications = functions.database.ref('/users/{userId}/following/{followingId}')
       //.onWrite(event => {
         .onCreate((snap,context) => {  


        console.info("Child value is val() " ,snap);


        var childNodeValue=snap.val();

        var topic=childNodeValue.userId;

        //var ref = firebase.database().ref.child('users');

        //console.log("testing ref pathName : " ,snap.ref.parent.parent.parent.pathname);
    //  console.log("testing ref : " ,snap.ref.parent.parent.parent.path);

        //var ref = admin.database().ref("users");

        //.child('users')

        return snap.ref.parent.parent.parent.orderByChild("userId").equalTo(childNodeValue.currentFollowingUserId)

     // .on('child_changed').then(snapshot => { once('value')
         .once('value', function(snapshot){ 
        var parentNodeValue=snapshot.val();

        console.info("Topic ID " ,topic);

        console.info("Parent value is val() " ,snapshot.val());

              var payload = {
            data: {
                username: parentNodeValue.userName,
                imageurl:parentNodeValue.userProfileImage,
                description:"Started Following You"
            }
        };



           // Send a message to devices subscribed to the provided topic.
        return admin.messaging().sendToTopic(topic, payload)
            .then(function (response) {
                // See the MessagingTopicResponse reference documentation for the
                // contents of response.
                console.log("Successfully sent message:", response);
                return response;
            })
            .catch(function (error) {
                console.log("Error sending message:", error);
                return error;
            });

      });








      });

数据库规则：

 "users" : {
    "1vWvSXDQITMmKdUIY7SYoLA1MgU2" : {
      "userEmail" : "test2kawee@gmail.com",
      "userId" : "1vWvSXDQITMmKdUIY7SYoLA1MgU2",
      "userName" : "Malik Abdul Kawee",
      "userPhoneNumber" : "",
      "userProfileImage" : "https://pbs.twimg.com/profile_images/1018741325875867648/ZnKeUiOJ_400x400.jpg"
    },
    "YJdwgRO08nOmC5HdEokr1NqcATx1" : {
      "following" : {
        "1vWvSXDQITMmKdUIY7SYoLA1MgU2" : {
          "currentFollowingUserId" : "YJdwgRO08nOmC5HdEokr1NqcATx1",
          "userEmail" : "test2kawee@gmail.com",
          "userId" : "1vWvSXDQITMmKdUIY7SYoLA1MgU2",
          "userName" : "Malik Abdul Kawee",
          "userPhoneNumber" : "",
          "userProfileImage" : "https://pbs.twimg.com/profile_images/1018741325875867648/ZnKeUiOJ_400x400.jpg"
        }
      },
      "userEmail" : "test2atif@gmail.com",
      "userId" : "YJdwgRO08nOmC5HdEokr1NqcATx1",
      "userName" : "Atif AbbAsi",
      "userPassword" : "test123",
      "userPhoneNumber" : "",
      "userProfileImage" : "http://paperlief.com/images/enrique-iglesias-body-workout-wallpaper-4.jpg"
    }
  }

    "users": {
     ".indexOn":  ["userId","currentFollowingUserId",".value"],
       "$userId": {
         "following": {
        //"$userId": {
             ".indexOn":  ["userId","currentFollowingUserId",".value"]
        }
    //}
       } 
}

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);


exports.sendFollowingNotifications = functions.database.ref('/users/{userId}/following/{followingId}')
       //.onWrite(event => {
         .onCreate((snap,context) => {  


        console.info("Child value is val() " ,snap);


        var childNodeValue=snap.val();

        var topic=childNodeValue.userId;

        //var ref = firebase.database().ref.child('users');

        //console.log("testing ref pathName : " ,snap.ref.parent.parent.parent.pathname);
    //  console.log("testing ref : " ,snap.ref.parent.parent.parent.path);

        //var ref = admin.database().ref("users");

        //.child('users')

        return snap.ref.parent.parent.parent.orderByChild("userId").equalTo(childNodeValue.currentFollowingUserId)

     // .on('child_changed').then(snapshot => { once('value')
         .once('value', function(snapshot){ 
        var parentNodeValue=snapshot.val();

        console.info("Topic ID " ,topic);

        console.info("Parent value is val() " ,snapshot.val());

              var payload = {
            data: {
                username: parentNodeValue.userName,
                imageurl:parentNodeValue.userProfileImage,
                description:"Started Following You"
            }
        };



           // Send a message to devices subscribed to the provided topic.
        return admin.messaging().sendToTopic(topic, payload)
            .then(function (response) {
                // See the MessagingTopicResponse reference documentation for the
                // contents of response.
                console.log("Successfully sent message:", response);
                return response;
            })
            .catch(function (error) {
                console.log("Error sending message:", error);
                return error;
            });

      });








      });

函数查询：

 "users" : {
    "1vWvSXDQITMmKdUIY7SYoLA1MgU2" : {
      "userEmail" : "test2kawee@gmail.com",
      "userId" : "1vWvSXDQITMmKdUIY7SYoLA1MgU2",
      "userName" : "Malik Abdul Kawee",
      "userPhoneNumber" : "",
      "userProfileImage" : "https://pbs.twimg.com/profile_images/1018741325875867648/ZnKeUiOJ_400x400.jpg"
    },
    "YJdwgRO08nOmC5HdEokr1NqcATx1" : {
      "following" : {
        "1vWvSXDQITMmKdUIY7SYoLA1MgU2" : {
          "currentFollowingUserId" : "YJdwgRO08nOmC5HdEokr1NqcATx1",
          "userEmail" : "test2kawee@gmail.com",
          "userId" : "1vWvSXDQITMmKdUIY7SYoLA1MgU2",
          "userName" : "Malik Abdul Kawee",
          "userPhoneNumber" : "",
          "userProfileImage" : "https://pbs.twimg.com/profile_images/1018741325875867648/ZnKeUiOJ_400x400.jpg"
        }
      },
      "userEmail" : "test2atif@gmail.com",
      "userId" : "YJdwgRO08nOmC5HdEokr1NqcATx1",
      "userName" : "Atif AbbAsi",
      "userPassword" : "test123",
      "userPhoneNumber" : "",
      "userProfileImage" : "http://paperlief.com/images/enrique-iglesias-body-workout-wallpaper-4.jpg"
    }
  }

    "users": {
     ".indexOn":  ["userId","currentFollowingUserId",".value"],
       "$userId": {
         "following": {
        //"$userId": {
             ".indexOn":  ["userId","currentFollowingUserId",".value"]
        }
    //}
       } 
}

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);


exports.sendFollowingNotifications = functions.database.ref('/users/{userId}/following/{followingId}')
       //.onWrite(event => {
         .onCreate((snap,context) => {  


        console.info("Child value is val() " ,snap);


        var childNodeValue=snap.val();

        var topic=childNodeValue.userId;

        //var ref = firebase.database().ref.child('users');

        //console.log("testing ref pathName : " ,snap.ref.parent.parent.parent.pathname);
    //  console.log("testing ref : " ,snap.ref.parent.parent.parent.path);

        //var ref = admin.database().ref("users");

        //.child('users')

        return snap.ref.parent.parent.parent.orderByChild("userId").equalTo(childNodeValue.currentFollowingUserId)

     // .on('child_changed').then(snapshot => { once('value')
         .once('value', function(snapshot){ 
        var parentNodeValue=snapshot.val();

        console.info("Topic ID " ,topic);

        console.info("Parent value is val() " ,snapshot.val());

              var payload = {
            data: {
                username: parentNodeValue.userName,
                imageurl:parentNodeValue.userProfileImage,
                description:"Started Following You"
            }
        };



           // Send a message to devices subscribed to the provided topic.
        return admin.messaging().sendToTopic(topic, payload)
            .then(function (response) {
                // See the MessagingTopicResponse reference documentation for the
                // contents of response.
                console.log("Successfully sent message:", response);
                return response;
            })
            .catch(function (error) {
                console.log("Error sending message:", error);
                return error;
            });

      });








      });

返回 snap.ref.parent.child（'users'）.orderByChild（'userId'）.equalTo（childNodeValue.currentFollowUserid）

我认为问题在于这个查询，我对以下节点的第一个查询返回了我的数据，但是当我检索其父节点用户的数据时，我得到了警告

我试图使用

functions.database.ref

，但它给出了以下异常

so I tried using this `snap.ref.parent.`to get reference of parent node.

Firebase函数，admin.database（）.ref（…）不是函数

Firebase函数，Functions.database（）.ref（…）不是函数

---

您在阅读用户时得到了错误的参考。您需要执行以下操作才能获得正确的引用：

snap.ref.parent.parent.parent

（ref现在将位于/users）。您的查询正在尝试读取以下项下的用户节点

警告是，您需要编写firebase规则以启用基于用户ID的索引，否则操作将占用大量带宽

以下是将添加索引的规则：

"users": {
   "$uid" : {
     ".indexOn" : ["userId"]
   }
}

以下是有关数据库规则的更多信息的资源：

这是firebase的一个简单工具，可以轻松编写规则：

---

附言：你回复了两个承诺，你上次发送通知的承诺将不起作用。使用firebase查询嵌套或链接它。还可以通过将（'child_changed'）上的

更改为
一次（'value'）
来创建查询单值事件
 错误消息末尾有一个尾随的
users
，这在JSON和规则中缺失。似乎您正在查询不存在的数据。@FrankvanPuffelen我认为这行返回snap.ref.parent.child（“用户”）的问题是，从以下节点获取数据后，我试图获取其父节点，但我不知道如何获取父节点，所以，我只是尝试使用snap.ref.parent。
snap.ref.parent.parent
？尽管我认为您可能正在寻找
snap.ref.root
。查看参考文档了解数据库的所有属性参考

：感谢@FrankvanPuffelen snap.ref.parent.parent.parent为我工作。查看数据库结构umar..我使用嵌套查询问题在于返回snap.ref.parent.child（“用户”）此查询。请参阅我的更新答案。在函数内部查询时，引用错误。是否有方法将引用打印为字符串。？与***/user/valueref类似，它是firebase sdk中的一个引用接口，并具有一个变量

path

，用于获取作为路径的引用。发送消息时出错：{Error:Messaging payload包含“data.userName”属性的无效值。值必须是字符串。如何解决此问题。？