Mongo 文档中的更新数组不起作用

Question

I have a user's collection, each user has a subscription array of objects. I want to add another subscription to that array. I'm getting the new subscription, updating it with findByIdAndUpdate , but it doesn't add the new subscription, however it shows that the document was updated. I tried several approaches but nothing worked well. Here is the last approach:

...
  const { user_id } = req.params;
  const subscription = req.body; // Getting subscription

  const user = await UserModel.findById(user_id).lean().exec(); // Getting user by id
  const { push_subscriptions } = user; // Getting subscribtions with destructuring
  const updated_subs = [...push_subscriptions, subscription];

  // Getting user another time and updating the push_subscriptions array
  const updated_user = await UserModel.findByIdAndUpdate(user_id, 
    {push_subscriptions: updated_subs},
    { new: true }
  ).exec();
...

Here are the logs of request body and params

// body
{
  endpoint: 'https://fcm.googleapis.com/fcm/send/cQ6wlRJ8t-s:APA91bEjqdLMzQLsroJ7zHzdjrzoshdPD8IJy_iIeRa8qV_Yjt6N1jeMUtyMq73wSn9JJT-4WXr_8uwHXttj-XFxHPCPAOqgN7zALsmf_BeIRZowRBTRHf9YH8v3AlcaZXWAIQ0qJNdn',
  expirationTime: null,
  keys: {
    p256dh: 'BBPC5h1QnBMPKMfPacgJu_2RFT7LAejyINh3CvP4pamkrlERr06YpRlSb7RbTUOn6MYW4adG93KfdEWXz68F9iQ',
    auth: 'Zl3iaOdBvihXG2QVOb26IQ'
  }
}
//params
{ user_id: '5fedc679f414663c693cf549' }

User schema, push_subscriptions part:

  push_subscriptions: {
    type: Array,
  },

Answer 1

Your query looks good, you can do single query using $push instead of doing manual process,

const { user_id } = req.params;
const subscription = req.body; 
const updated_user = await UserModel.findByIdAndUpdate(user_id, 
    { 
        $push: {
            push_subscriptions: subscription
        },
    { new: true }
).exec();