我必须为Android开发一个应用程序，让人们登录并添加游乐园的Theyr数据，并且我还需要一个应用程序来查看数据库中的数据，例如：PC上的姓名，生日，儿童等，我尝试了Web应用程序，但我在将其连接到数据库时遇到问题。我是数据库新手，所以可能来自我的代码，有人可以帮助我吗？我将在下面添加我的代码。该应用程序仅需要始终向我显示数据库并在有人注册时进行更新
我得到的错误在照片中
<html>
<head>
<meta charset="utf-8"/>
<script src="https://www.gstatic.com/firebasejs/7.6.1/firebase-app.js"></script>
<script src="https://www.gstatic.com/firebasejs/7.6.1/firebase-analytics.js"></script>
<title>Freaky Firebase Example</title>
</head>
<body>
<h1>Freaky Firebase Realtime Database Example</h1>
<pre id='object'></pre>
<script>
(function(){
// Initialize Firebase
var firebaseConfig = {
apiKey: "XXXXXXXXXXXXXXXXXXXXXXXXXXXX",
authDomain: "XXXXXXXXXXXXXXXXXXXXXXXXXXXX.com",
databaseURL: "XXXXXXXXXXXXXXXXXXXXXXXXXXXX.com",
projectId: "XXXXXXXXXXXXXXXXXXXXXXXXXXXX",
storageBucket: "XXXXXXXXXXXXXXXXXXXXXXXXXXXX.com",
messagingSenderId: "XXXXXXXXXXXXXXXXXXXXXXXXXXXX",
appId: "XXXXXXXXXXXXXXXXXXXXXXXXXXXX",
measurementId: "XXXXXXXXXXXXXXXXXXXXXXXXXXXX[enter image description here][1]"
};
firebase.initializeApp(firebaseConfig);
firebase.analytics();
var userDataRef = firebase.database().ref("UserData").orderByKey();
userDataRef.once("value").then(function(snapshot) {
snapshot.forEach(function(childSnapshot) {
var key = childSnapshot.key;
var childData = childSnapshot.val();
var name_val = childSnapshot.val().Name;
var id_val = childSnapshot.val().AssignedID;
$("#name").append(name_val);
$("#id").append(id_val);
});
});
/* Data Event Listeners Start */
const preObject = document.getElementById('object');
const dbRefObject = firebase.database().ref().child('object');
dbRefObject.on('value', snap => {
console.log(snap.val());
preObject.innerText = JSON.stringify(snap.val(), null, 3);
}, function(error) {
// The fetch failed.
console.error(error);
});
/* Stop */
}());
</script>
</body>
</html>
与firebase-app和firebase-analytics一起，您必须导入firebase-database服务。
<script src="https://www.gstatic.com/firebasejs/7.6.1/firebase-database.js"></script>