节点没有从Firebase数据库中删除？

Question

我有以下数据结构：

不幸的是，＆＃39; days＆＃39;不会使用下面的代码从数据库中删除。

我目前的代码：

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

     exports.deleteOldItems = functions.database.ref('/path/to/items/{pushId}') //irrelevant to the question
    .onWrite(event => {
      var ref = event.data.ref.parent; // reference to the items
      var now = Date.now();
      var cutoff = now - 2 * 60 * 60 * 1000;
      var oldItemsQuery = ref.orderByChild('timestamp').endAt(cutoff);

  return oldItemsQuery.once('value', function(snapshot) {
    // create a map with all children that need to be removed
    var updates = {};
    snapshot.forEach(function(child) {
      updates[child.key] = null
    });
    // execute all updates in one go and return the result to end the function
    return ref.update(updates);
  }).then(function() {;
    return functions.database.ref('/days').remove(); // /days doesn't get removed!
  });

    });

Answer 1

你可以这样做：

let updates = {};
updates['/days'] = null;

firebase.database().ref().update(updates);

请参阅docs;

中的“更新或删除数据”

在您的代码中：

.then(function() {;
    let updates = {};
    updates['/days'] = null;

    return firebase.database().ref().update(updates)
});

编辑：尝试以下内容：

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

...

let updates = {};
updates['/days'] = null;
defaultDatabase.ref().update(updates);

参考：https://firebase.google.com/docs/database/admin/start