Javascript 从Firebase实时数据库获取单个元素
如果有人能帮忙,我将不胜感激 我试图从firebase数据库中接收单个元素,并将所述元素放入表中。我已经完成了一次任务,但没有正确保存,我花了很长时间试图重新配置js 我的目标是从特定的团队ID获取用户名,例如1009254444 数据库为结构化数据/xbox/3787955/teams/10925444用户名值在此元素“”中 到目前为止,我掌握的代码是 HTMLJavascript 从Firebase实时数据库获取单个元素,javascript,firebase,firebase-realtime-database,Javascript,Firebase,Firebase Realtime Database,如果有人能帮忙,我将不胜感激 我试图从firebase数据库中接收单个元素,并将所述元素放入表中。我已经完成了一次任务,但没有正确保存,我花了很长时间试图重新配置js 我的目标是从特定的团队ID获取用户名,例如1009254444 数据库为结构化数据/xbox/3787955/teams/10925444用户名值在此元素“”中 到目前为止,我掌握的代码是 HTML <!-- The core Firebase JS SDK is always required and must
<!-- The core Firebase JS SDK is always required and must be listed first -->
<script src="https://www.gstatic.com/firebasejs/7.13.2/firebase.js"></script>
<div class="table-responsive">
<table class="table table-hover table-standings sortable">
<table>
<thead>
<th>Coach</th>
</thead>
<tbody id='userName'></tbody>
</table>
</table>
</div>
js
table {
border-collapse: collapse;
width: 100%;
}
th,
td {
padding: 3px;
text-align: center;
border-bottom: 1px solid #ddd;
}
tr:hover {
background-color: #aa010b;
color: #ffffff;
}
// Your web app's Firebase configuration
var firebaseConfig = {
apiKey: "****",
authDomain: "****",
databaseURL: "****",
projectId: "cfm-stats",
storageBucket: "****",
messagingSenderId: "****",
appId: "****",
measurementId: "****"
}
;
firebase.initializeApp(firebaseConfig);
var rootRef = firebase.database().ref('data/xbox/3787955/teams');
var ref = rootRef.child('1009254444');
ref.on('value', function(snap) {
document.getElementById("userName").innerHTML = "";
snap.forEach(function(child) {
var childData = child.val();
var userName = childData.userName;
document.getElementById("userName").innerHTML += "<tr><td> " + userName + "</td></tr>";
});
}
);
//您的web应用的Firebase配置
var firebaseConfig={
apiKey:“*****”,
authDomain:“*****”,
数据库URL:“*****”,
projectId:“cfm统计数据”,
storageBucket:“*****”,
messagingSenderId:“*****”,
appId:“*****”,
计量单位:“*****”
}
;
firebase.initializeApp(firebaseConfig);
var rootRef=firebase.database().ref('data/xbox/3787955/teams');
var ref=rootRef.child('1009254444');
参考on(值),功能(捕捉){
document.getElementById(“用户名”).innerHTML=“”;
snap.forEach(函数(子函数){
var childData=child.val();
var userName=childData.userName;
document.getElementById(“用户名”).innerHTML+=“用户名+”;
});
}
);
这似乎是相关的代码:
firebase.initializeApp(firebaseConfig);
var rootRef = firebase.database().ref('data/xbox/3787955/teams');
var ref = rootRef.child('1009254444');
ref.on('value', function(snap) {
document.getElementById("userName").innerHTML = "";
snap.forEach(function(child) {
var childData = child.val();
var userName = childData.userName;
document.getElementById("userName").innerHTML += "<tr><td> " + userName + "</td></tr>";
});
}
);
现在在回调中执行snap.forEach
。但是您正在阅读的JSON中没有重复的结构,因此这个forEach
实际上将在每个属性上循环:abbrName
,awayloss
,awayies
,等等
您可能希望删除循环:
ref.on('value', function(snap) {
document.getElementById("userName").innerHTML = "";
var childData = snap.val();
var userName = childData.userName;
document.getElementById("userName").innerHTML += "<tr><td> " + userName + "</td></tr>";
}
);
ref.on('value',函数(捕捉){
document.getElementById(“用户名”).innerHTML=“”;
var childData=snap.val();
var userName=childData.userName;
document.getElementById(“用户名”).innerHTML+=“用户名+”;
}
);
或者,在树中听高一级,这样您可以得到所有团队:
firebase.initializeApp(firebaseConfig);
var rootRef = firebase.database().ref('data/xbox/3787955/teams');
rootRef.on('value', function(snap) {
document.getElementById("userName").innerHTML = "";
snap.forEach(function(child) {
var childData = child.val();
var userName = childData.userName;
document.getElementById("userName").innerHTML += "<tr><td> " + userName + "</td></tr>";
});
}
);
firebase.initializeApp(firebaseConfig);
var rootRef=firebase.database().ref('data/xbox/3787955/teams');
rootRef.on('value',函数(snap){
document.getElementById(“用户名”).innerHTML=“”;
snap.forEach(函数(子函数){
var childData=child.val();
var userName=childData.userName;
document.getElementById(“用户名”).innerHTML+=“用户名+”;
});
}
);
您的问题中包含了一幅JSON树的图片,不幸的是,这并没有为我们提供很多数据路径的上下文。请将其替换为实际的JSON文本,您可以通过单击溢出菜单中的导出JSON链接轻松获得该文本(⠇) 当然。将JSON作为文本可以进行搜索,使我们能够轻松地使用它来测试您的实际数据,并在我们的答案中使用它,这通常是一件好事。我已经用JSON链接替换了图像。由于数据库的大小,将文本放在这里会很混乱。
firebase.initializeApp(firebaseConfig);
var rootRef = firebase.database().ref('data/xbox/3787955/teams');
rootRef.on('value', function(snap) {
document.getElementById("userName").innerHTML = "";
snap.forEach(function(child) {
var childData = child.val();
var userName = childData.userName;
document.getElementById("userName").innerHTML += "<tr><td> " + userName + "</td></tr>";
});
}
);