Question

This is the data that i want to retrieve

How can I retrieve the data without knowing the unique ID?

        var query = firebase.database().ref("/Venue").orderByKey();
    query.on("value", function (snapshot) {
            snapshot.forEach(function (childSnapshot) {
                var key = childSnapshot.key;
                var childData = childSnapshot.val();
                console.log(childData);                                                                                         
            });
        });

Answer 1

使用<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <div class="wrapper"> <div class="wrapperleft"> <div class="bio"> <ul> <div id="generationbutton" class="opacity"> <li>01 Generation Anxiety</li> </div> <div id="lekhenabutton" class="opacity"> <li>02 Lekhenaporter.com</li> </div> <div id="bodysbutton" class="opacity"> <li>03 Body(s) Under Negotiation</li> </div> <div id="glitterbutton" class="opacity"> <li>04 Glitter Boy Cosmetics</li> </div> <div id="juicebutton" class="opacity"> <li>05 Juice WRLD Cover Art</li> </div> </ul> </div> <div class="back"> <h1>← Back</h1> </div> </div> <div class="wrapperright"> <div class="display"> <img src="http://media-s3-us-east-1.ceros.com/vevo/images/2017/11/07/8d018e81643b41c3561b5ab4f5bf504b/iamddb-contact-sheet1.jpg" /> </div> <div id="generationanxiety"> <img src="https://dazedimg-dazedgroup.netdna-ssl.com/786/azure/dazed-prod/1180/0/1180791.jpg" /> </div> <div id="lekhenaporter"> <img src="http://kendrickbrinson.com/wp-content/uploads/2014/03/YoungThug_Portraits-029.jpg" /> </div> <div id="bodys"> <img src="https://www.thunderstudios.com/wp-content/uploads/2016/03/Calvin-15.jpg" /> </div> <div id="glitter"> <img src="https://4c79id2ej5i11apui01ll2wc-wpengine.netdna-ssl.com/wp-content/uploads/2018/01/IAMDDB-Gallery-3.jpg" /> </div> <div id="juice"> <img src="https://www.thunderstudios.com/wp-content/uploads/2016/03/Calvin-15.jpg" /> </div> </div> </div>来提供帮助。它返回对象属性值的数组

由于Object.values仅具有一个属性，因此您可以轻松获取其值，它将位于索引0处

.Data

Answer 2

您可以获得对象javascript的第一键

Object.keys(childData.Data)[0];

获取对象javascript的第一键值

Object.values(childData.Data)[0];

var obj = {
  Venue: {
    Block_A: {
      Data:  {
        lpanss :{
          Date: "19/03/2019",
          Humi: 30,
          Temp: 50,
          Time: "12:56"
        }
       }
    }
  }
};

//key
console.log(Object.keys(obj.Venue.Block_A.Data)[0]);
//values
console.log(Object.values(obj.Venue.Block_A.Data)[0]);

Answer 3

使用Object.values：

var obj = {
  Venue: {
    Block_A: {
      Data: {
        Date: "19/03/2019",
        Humi: 30,
        Temp: 50,
        Time: "12:56"
      }
    }
  }
};
console.log(Object.values(obj.Venue.Block_A.Data));

如何从对象检索数据[Firebase唯一密钥]

3 个答案: