Firebase Cloud Functions 在 24 小时后直接删除节点

Question

我的目标是在使用 Firebase Cloud Functions 和实时数据库发送消息节点后 24 小时删除所有消息节点。我尝试从this post 复制并粘贴答案，但由于某种原因，消息在创建后直接删除，而不是在 24 小时后删除。如果有人可以帮助我解决这个问题，我将不胜感激。我已经根据同一个问题尝试了多个不同的答案，但它们对我没有用。

这是我的 index.js 文件：

'use strict';

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

// Cut off time. Child nodes older than this will be deleted.
const CUT_OFF_TIME = 24 * 60 * 60 * 1000; // 2 Hours in milliseconds.


exports.deleteOldMessages = functions.database.ref('/Message/{chatRoomId}').onWrite(async (change) => {
const ref = change.after.ref.parent; // reference to the parent
const now = Date.now();
const cutoff = now - CUT_OFF_TIME;
const oldItemsQuery = ref.orderByChild('seconds').endAt(cutoff);
const snapshot = await oldItemsQuery.once('value');
// create a map with all children that need to be removed
const updates = {};
snapshot.forEach(child => {
updates[child.key] = null;
});
// execute all updates in one go and return the result to end the function
return ref.update(updates);
});

而我的数据库结构是：

Answer 1

在 cmets 中，您表示您正在使用 Swift。从那和屏幕截图可以看出，自 1970 年以来，您以秒为单位存储时间戳，而 Cloud Functions 中的代码假定它以毫秒为单位。

最简单的解决方法是：

// Cut off time. Child nodes older than this will be deleted.
const CUT_OFF_TIME = 24 * 60 * 60 * 1000; // 2 Hours in milliseconds.


exports.deleteOldMessages = functions.database.ref('/Message/{chatRoomId}').onWrite(async (change) => {
    const ref = change.after.ref.parent; // reference to the parent
    const now = Date.now();
    const cutoff = (now - CUT_OFF_TIME) / 1000; // convert to seconds
    const oldItemsQuery = ref.orderByChild('seconds').endAt(cutoff);
    const snapshot = await oldItemsQuery.once('value');
    // create a map with all children that need to be removed
    const updates = {};
    snapshot.forEach(child => {
        updates[child.key] = null;
    });
    // execute all updates in one go and return the result to end the function
    return ref.update(updates);
});

也可以在这里查看我的答案：How to remove a child node after a certain date is passed in Firebase cloud functions?