Mongodb-Nodejs Pull Element From An Array

Asked Jul 04 '20 at 14:22

Active Jul 04 '20 at 20:50

Viewed 170 times

Guys I want to $pull an element from array. Here:

User's Follow:

{ follow:
   [ 5edfe8f3bfc9d677005d55ca,
     5edfe92fbfc9d677005d55cc,
     5ee2326cc7351c5bb0b75f1a ],

follow id:(Which we will pull)

5edfe92fbfc9d677005d55cc

The process:

    .
    .
    
    User.update(user,{$pull: { follow: friend}}, function(err){
          if(err){
          console.log(err);
        }else{
          res.send("Success")
        } 
        });
    .
    .

Also I have tried with $elemMatch: Mongodb Unfollow With $pull

Question: How to $pull specific element from an array?

But it doesnt work. Can someone help me to solve this problem ?

Note: Guys the id's are given as an example to understand well. The follow is the friends of current user. And if user wants to unfollow then it will $pull the friend(friend: the user on the profile page) Think like facebook's follow-unfollow request. So that if you want to answer please do not give example with id's above because follow id's always change user to user.

So how to pull specific element from an array?

Full Code:

app.post('/cikar/:id', function(req, res){

  User.find(req.user
  
  ).exec(function(err, user){
  
  if(err){
    console.log(err);
  }
    
    User.find({"username":req.params.id}, function(err, friend){
      
      if(err){
        console.log(err);
      }
    User.update(user,{$pull: { follow: friend}}, function(err){
      if(err){
      console.log(err);
    }else{
      res.send("Success")
    } 
    });
  });
  });
  });

edited Jul 04 '20 at 20:50

asked Jul 04 '20 at 14:22

Ö. ALP EREN GÜL

[This](https://stackoverflow.com/questions/4969768/removing-the-array-element-in-mongodb-based-on-the-position-of-element#:~:text=Here%27s%20your%20answer%20MongoDB%20pull%20array%20element%20from,every%20element%20of%20this%20array%20is%20an%20object%3A) may be what you need – MTN Jul 04 '20 at 14:28
I have eddited the question. In my project there is no certain ids because friends(follow) changes user to user – Ö. ALP EREN GÜL Jul 04 '20 at 14:32
Can you show your schema please? Your query looks okay to me. Also, is `friend` an object or `friend's ID`? – Ravi Shankar Bharti Jul 04 '20 at 16:03
friend is the user on the profile. Like owner of the profile – Ö. ALP EREN GÜL Jul 04 '20 at 17:33
About schema: Follower is an object id – Ö. ALP EREN GÜL Jul 04 '20 at 17:33
push query works fine but pull doesnt – Ö. ALP EREN GÜL Jul 04 '20 at 17:33
Any suggestions? – Ö. ALP EREN GÜL Jul 04 '20 at 18:49
Make sure the datatype matches. The `$pull` is processed by the mongod not by mongoose, so there is no implicit type conversion. `{$pull: "5edfe8f3bfc9d677005d55ca"}` will not do anything if the array contains `[ObjectId("5edfe8f3bfc9d677005d55ca")]` – Joe Jul 04 '20 at 19:18
But same codes with $push or $addToSet works fine – Ö. ALP EREN GÜL Jul 04 '20 at 20:36
Can you provide some sample code that we can run to reproduce the problem? – Joe Jul 04 '20 at 20:40
I have added full code. Can you look at it please? – Ö. ALP EREN GÜL Jul 04 '20 at 20:50
Does the follow array include the entire friend object? User.find will return a document, if follow only contains the _id, try `User.update(user,{$pull: { follow: friend._id}}` – Joe Jul 06 '20 at 02:32
I have tried that but it didnt work – Ö. ALP EREN GÜL Jul 07 '20 at 09:53
Array show like this: 5edfe8f3bfc9d677005d55ca – Ö. ALP EREN GÜL Jul 07 '20 at 10:13
Again it works when I do push or addtoset – Ö. ALP EREN GÜL Jul 07 '20 at 10:14
hmm it says friend._id is undefined but – Ö. ALP EREN GÜL Jul 07 '20 at 11:20
It shows friend but when I want to take just _id it says undefined – Ö. ALP EREN GÜL Jul 07 '20 at 11:20

Mongodb-Nodejs Pull Element From An Array

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