How can mongoose further filter the key for the documents it queries?

  node.js, question

1. Through the static method added in the schema layer, the collection of array documents is found out. How to further delete the unwanted key values
Code:

//Schema
 var ProductSchema = new mongoose.Schema({
 productId: Number,
 productTitle: String,
 productCover: {
 url: String,
 description : String
 },
 categroyType: Number,
 })
 //Static
 ProductSchema.statics.getByCategory = function(category,cb){
 return this.where('categroyType').equals(category).select({_id:0,meta:0,__v:0})
 .exec(cb);
 
 Then the model layer directly uses the static method, ignoring the module dependency of the model ~
 
 Product.getByCategory(1,function(err,product){
 if (err){
 console.log(err)
 bracket
 else{
 How can document collection in the form of array found here in console.log(product) // delete unnecessary key-value pairs?
 bracket
 })

Only provide ideas, not verified.

Method 1: delete item one by one

Call remove for every item in product inside

return Promise.all(product.map(item=>item.remove()))

Method 2: delete according to id

Extract all ids in product

return Product.remove({_id:{$in:product.map(item=>item._id)}},{multi:true})