在 Cloud Functions for Firebase 中访问数据库数据

Question

在 Cloud Functions for Firebase 中，例如：

exports.makeUppercase = functions.database.ref('/messages/{pushId}/original')
    .onWrite(event => {
    //how to access data at another node, for example 
    //important/messages/{pushId}
})

如何读取另一个节点的数据，例如/important/messages/{pushId}？谢谢

Answer 1

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);

exports.makeUppercase = functions.database.ref('/messages/{pushId}/original').onWrite(event => {
   const getSomethingPromise = admin.database().ref(`/important/messages/{pushId}`).once('value');
   return getSomethingPromise.then(results => {
            const somethingSnapshot = results[0];
            // Do something with the snapshot
        })
    })

例如检查这个例子：https://github.com/firebase/functions-samples/blob/master/fcm-notifications/functions/index.js