英文:
How do a assign a firebase database value to a variable in javascript?
问题
是否有一种方法可以将变量分配给实时数据库的值？如果可以的话，我可以得到一些帮助吗？
英文:
I don't have any code because this is just a theoretical idea. But would there be a way to assign a variable to a realtime database value? If so, could I get some help?
答案1
得分: 1
让我们假设您有以下数据库结构：
user: 123
name: user
假设您想要获取 name 的值一次并将其分配为变量，然后在控制台中记录它。
由于您想要使用 Firebase 的 get()，您将使用以下代码：
import { getDatabase, ref, child, get } from "firebase/database";
const dbRef = ref(getDatabase());
get(child(dbRef, `123`))
.then((snapshot) => {
snapshot.forEach((child) => {
let name = child.val(); // user
console.log(hello);
let key = child.key; // name
console.log(key);
});
})
.catch((error) => {
console.error(error);
});
在上述代码中，我访问了 123 并使用 forEach 遍历快照（在本例中只有一个 - name），我将其称为 child。child.val() 将打印 user（即文档的值），而 child.key 将打印 name（即文档的键），我可以轻松将它们分配给变量并在任何地方使用，比如 console.log()。
我已经个人测试了这段代码，但它应该按预期工作。
英文:
Let's say you have the following database structure:
user: 123
name: user
And let's say you want to get the value of name once and assign it as a variable and log it in the console.
And since you want to use Firebase's get(), you'll use:
import { getDatabase, ref, child, get } from "firebase/database";
const dbRef = ref(getDatabase());
get(child(dbRef, `123`))
.then((snapshot) => {
snapshot.forEach((child) => {
let name = child.val(); // user
console.log(hello);
let key = child.key; // name
console.log(key);
});
})
.catch((error) => {
console.error(error);
});
In the above code, I access 123 and forEach snapshot (which in this case only one - name), I'll call it child. And child.val() will print user (aka the value of the document) and child.key will print name (aka the key of the document) and I can easily assign them to variables and use them anywhere like console.log().
I've tested the code personally, but it should work as expected.
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论