使用Javascript从Firebase检索数据时出现错误

我将这些cdn包括在我的html中：

<script src="https://www.gstatic.com/firebasejs/7.6.1/firebase-app.js"></script>

<script src="https://www.gstatic.com/firebasejs/3.1.0/firebase-auth.js"></script>

<script src="https://www.gstatic.com/firebasejs/3.1.0/firebase-database.js"></script> 

<script src="StoreFeatured.js" type="text/javascript"></script>

我做错了什么

我收到这些错误：

> firebase-auth.js:206 Uncaught Error: Cannot find the firebase namespace; be sure to include firebase-app.js before this library.
    at firebase-auth.js:206
    at firebase-auth.js:206
    at firebase-auth.js:206
> 
> firebase-database.js:38 Uncaught Error: FIREBASE FATAL ERROR: Failed
> to register the Firebase Database Service (TypeError:
> firebase.INTERNAL.registerService is not a function) 
>     at dd (firebase-database.js:38)
>     at firebase-database.js:245
>     at firebase-database.js:245
> 
> StoreFeatured.js:17 Uncaught TypeError: firebase.database is not a
> function
>     at new GetData (StoreFeatured.js:17)
>     at StoreFeatured.js:13

getdata（）的第一行是做问题，我想我对cdn做了一些错误的事情。。。请帮忙

如果删除cdn，则会出现一个错误：

StoreFeatured.js:16 Uncaught TypeError: firebase.database is not a function
at new GetData (StoreFeatured.js:16)
at StoreFeatured.js:13

---

将firebase auth和firebase数据库更新为以下版本：

<script src="https://www.gstatic.com/firebasejs/7.6.1/firebase-auth.js"></script>
<script src="https://www.gstatic.com/firebasejs/7.6.1/firebase-database.js"></script>

---

不要使用各种CDN，而是使用一个包含所有库的CDN：

script src="https://www.gstatic.com/firebasejs/7.14.4/firebase.js" 

---

您不应该在所有firebase依赖项中使用相同的版本吗？我看到了

7.6.1

和

3.1.0

。我从一个答案中复制了它，没有看它：（非常感谢你没有意识到它这么简单！

script src="https://www.gstatic.com/firebasejs/7.14.4/firebase.js"