How do I push my new item without creating new mongoose item

Question

I want to append or push my new items that I input in the array without creating new mongoose schema..what I mean is that I will only push items without creating new _id...Here is my code..

For mongoose.Schema()

const mainSchema = new Schema({
    likes:{
        type:Number,
        max:100000
    },
    people:[{
        key:{type:String},
        name:{type:String}
    }]
},{
    timestamps:true
})

And for the routes that will post my items..

router.route('/item/1').post((req,res) => {

    const { likes, people } = req.body


    const FirstItem = Main({
        likes,
        // people
    })

    FirstItem.people.push(people)

    FirstItem.save()
        .then(likes => res.json('New User Added'))
        .catch(err => res.status(400).json('Error :' + err))

})  

As you see I didn't input new Main({}) in my post because I don't wanna create a new _id..but I want to push my items in my array whenever I create another new items....This is how I write it in postman..

{
    "likes":0,
    "people":[
        {
            "key":"Tes22t",
            "name":"Tit213an"
        }
    ]
}

Now if I changed something after posting this in my POST method. like "key":"testetsee","name":"123123123" it will give me an error like this ... "Error :ValidationError: people.0._id: Cast to ObjectId failed for value \"[ { key: 'Tes22t', name: 'Tit213an' } ]\" (type Array) at path \"_id\""

I think my problem here is pushing the item? or the post? or do I just need to update it?

EDITED

I have this in my frontend to pass it to my backend because I want my each item to received whose account has registered so that it can store the username and keys..

axios.post('http://localhost:7171/likes/item/'+1,{ people:{name:name,key:key }})
          axios.post('http://localhost:7171/likes/item/'+2,{ people:{name:name,key:key } })
          axios.post('http://localhost:7171/likes/item/'+3,{ people:{name:name,key:key } })
          axios.post('http://localhost:7171/likes/item/'+4,{ people:{name:name,key:key } })
          axios.post('http://localhost:7171/likes/item/'+5,{ people:{name:name,key:key } })

And then the code you give me sir is here ...

router.route('/item/:id').post((req,res) => {

    const id = req.params.id
    
    console.log(id)

    if (!id) return res.status(400).json({ message: "missing id" });

    const { likes, people } = req.body;

    Main
        .updateOne(
        { _id: id },
        {
            $addToSet: { people: { $each: people } },
            $set: {
                likes,
            },
        },
        )
        .then((likes) => res.json({ message: "New User Added" }))
        .catch((err) => res.status(400).json("Error :" + err));

})  

Since there is 5 items that I will post simultaneously, then It should have 5 items in my database and will update the array whenever I have new user to append it in my list of array in each item object.

What I received in my postman is this... "Error :CastError: Cast to ObjectId failed for value \"1\" (type string) at path \"_id\" for model \"liker-model\""

Answer 1

If you only want push an element into people array of that object, you should use updateOne() instead of save()

So the code will like

router.route('/item/1').post((req,res) => {

    const { likes, people } = req.body

    const model = mongoose.model('collection_name', mainSchema);

    model.updateOne({like}, {$addToSet: { people: {$each: people} }})
        .then(likes => res.json('New User Added'))
        .catch(err => res.status(400).json('Error :' + err))


})  

---

after discuss with the thread owner, i create new answer with the /1 as item id

const _ = require("lodash");

router.route("/item/:id").post((req, res) => {
  const id = _.get(req, "params.id");
  if (!id) return res.status(400).json({ message: "missing id" });
  const { likes, people } = req.body;

  const model = mongoose.model("collection_name", mainSchema);

  model
    .updateOne(
      { _id: id },
      {
        $addToSet: { people: { $each: people } },
        $set: {
          likes,
        },
      },
    )
    .then((likes) => res.json({ message: "New User Added" }))
    .catch((err) => res.status(400).json("Error :" + err));
});