问firebase云函数不更新数据

EN

exports.quarter = functions.https.onRequest((req, res) => {
 let user1 = admin.database().ref('users/user1/userDetails').once('value');
 let user2 = admin.database().ref('users/user2/userDetails').once('value');
 let user3 = admin.database().ref('users/user3/userDetails').once('value');
 let user4 = admin.database().ref('users/user4/userDetails').once('value');
  Promise.all([user1, user2, user3, user4])
      .then(result => {
    let data = {};
     result[0].forEach(action => {
         data['users/user1/userDetails/' + action.key + '/' + 'Rating'] = 0;
     });
     result[1].forEach(action => {
         data['users/user2/userDetails/' + action.key + '/' + 'Rating'] = 0;
     });
    result[2].forEach(action => {
        data['users/user3/userDetails/' + action.key + '/' + 'Rating'] = 0;
    });
    result[3].forEach(action => {
        data['users/user4/userDetails/' + action.key + '/' + 'Rating'] = 0;
    });
     return data;

}).then(data => {
      console.log(data);
     return  admin.database().ref().update(data);

 }).then(data => {
     return res.send('done');

 }).catch(error => {
    return res.status(500).send(error);
 })
});