firebase读取和写入在一个事件中

// 引入 Firebase
import firebase from 'firebase/app';
import 'firebase/database';

// 初始化 Firebase
const firebaseConfig = {
    apiKey: "YOUR_API_KEY",
    authDomain: "YOUR_PROJECT_ID.firebaseapp.com",
    databaseURL: "https://YOUR_PROJECT_ID.firebaseio.com",
    projectId: "YOUR_PROJECT_ID",
    storageBucket: "YOUR_PROJECT_ID.appspot.com",
    messagingSenderId: "YOUR_MESSAGING_SENDER_ID",
    appId: "YOUR_APP_ID"
};

firebase.initializeApp(firebaseConfig);

// 读取和写入数据的函数
function readAndWriteData() {
    const dbRef = firebase.database().ref('path/to/data');

    // 读取数据
    dbRef.once('value')
        .then(snapshot => {
            const data = snapshot.val();
            console.log('读取的数据:', data);

            // 根据读取的数据进行写入
            const newData = {
                ...data,
                additionalField: 'newValue' // 添加新字段
            };

            // 写入数据
            return dbRef.set(newData);
        })
        .then(() => {
            console.log('数据写入成功');
        })
        .catch(error => {
            console.error('发生错误:', error);
        });
}

// 调用函数
readAndWriteData();

// 引入 Firebase
import firebase from 'firebase/app';
import 'firebase/firestore';

// 初始化 Firebase
const firebaseConfig = {
    apiKey: "YOUR_API_KEY",
    authDomain: "YOUR_PROJECT_ID.firebaseapp.com",
    projectId: "YOUR_PROJECT_ID",
    storageBucket: "YOUR_PROJECT_ID.appspot.com",
    messagingSenderId: "YOUR_MESSAGING_SENDER_ID",
    appId: "YOUR_APP_ID"
};

firebase.initializeApp(firebaseConfig);

// 读取和写入数据的函数
async function readAndWriteData() {
    const db = firebase.firestore();
    const docRef = db.collection('yourCollection').doc('yourDocument');

    try {
        // 读取数据
        const doc = await docRef.get();
        if (doc.exists) {
            const data = doc.data();
            console.log('读取的数据:', data);

            // 根据读取的数据进行写入
            const newData = {
                ...data,
                additionalField: 'newValue' // 添加新字段
            };

            // 写入数据
            await docRef.set(newData);
            console.log('数据写入成功');
        } else {
            console.log('文档不存在');
        }
    } catch (error) {
        console.error('发生错误:', error);
    }
}

// 调用函数
readAndWriteData();