Question

我无法弄清楚我在做什么错，因此需要额外的眼睛来找出我在做什么错。我正在尝试从Delete firebase data older than 2 hours获得问题的答案，该问题的答案是使用https://github.com/firebase/functions-samples/tree/master/delete-old-child-nodes和https://github.com/firebase/functions-samples/blob/master/delete-old-child-nodes/functions/index.js在一段时间后删除节点。

/root
  /items
    LoHgJSFt8hHi2o_hP: {
      timestamp: 1497911193083,
      ...some_other_data
    },
    LoHgJSsGGHi2o_fD: {
      timestamp: 1597911193083  
      ...some_other_data                  
    }

我的index.js看起来像

//index.js
const functions = require('firebase-functions');
const admin = require('firebase-admin');
const { createUser } = require('./auth/onCreate');
const { deleteOldData } = require('./auth/onDeleteOldData');
const serviceAccount = require('./ownerstown-admin.json');
admin.initializeApp({
  credential: admin.credential.cert(serviceAccount),
  databaseURL: 'https://ownexxxxxxxx-c86cf.firebaseio.com'
});
exports.createUser = functions.firestore.document('users/{userId}').onCreate(createUser);
exports.deleteOldData = functions.database.ref('/referralIds/ids/{pushId}').onWrite(deleteOldData);

然后是onDeleteOldData.js

// auth/onDeleteOldData.js
const CUT_OFF_TIME = 2 * 60 * 60 * 1000;
async function deleteOldData(change) {
  console.log('starting nooowwwwwww');
  const ref = change.after.ref.parent;
  console.log('ref', ref);
  const now = Date.now();
  const cutoff = now - CUT_OFF_TIME;
  const oldItemsQuery = ref.orderByChild('timestamp').endAt(cutoff);
  const snapshot = await oldItemsQuery.once('value');
  console.log('snapshot', snapshot);
  const updates = {};
  snapshot.forEach(child => {
    updates[child.key] = null;
  });
  return ref.update(updates);
}
module.exports = {
  deleteOldData
};

并按一下按钮将数据推送

  function createLoginId() {
    const rootRef = Firebase.database.ref();
    const allDetails = rootRef.child('referralIds/ids');
    const timeStamp = Date.now();
    const someId = uuidv4();
    const { origin } = window.location;
    const data = {
      timeStamp,
      someId,
      createrId: id
    };
    const newRef = allDetails.push();
    newRef.set(data);
  }

但是一旦我推送数据，它就会在几秒钟内被删除。

怎么了？

Answer 1

问题来自于这样一个事实：当您写入数据库时，您会进行操作

const timeStamp = Date.now();
//...
const data = {
  timeStamp,
  someId,
  createrId: id
};

这意味着您保存了字段timeStamp，但是您的Cloud Function根据timestamp选择要删除的节点（全部为小写）。

实时数据库中的节点名称区分大小写。

顺便说一句，请注意，您可以使用时间戳记

const timestamp = firebase.database.ServerValue.TIMESTAMP;

“用于自动填充Firebase服务器确定的当前时间戳的占位符”，请参见https://firebase.google.com/docs/reference/js/firebase.database.ServerValue

2小时后要求删除的Firebase自动删除功能删除元素（以秒为单位）

1 个答案: