Find duplicate enteries from collection node js? - node.js

Question

I want to find out duplicate entries on the basis of field " name " and in the result, I want to fetch " name " and " _id ".
I have tried using aggregate function and it is returning all the result from database as null:
here is my code:
ModelRestaurant.aggregate((
// { "$group": { "_id": "$name", "count": { "$sum": 1 } } },
// { "$match": { "_id": { "$ne": null }, "count": { "$gt": 1 } } },
// { "$project": { "name": "$_id", "_id": 0 } }
{ $group: { "_id": "$name", "name": { $first: "$name" }, "count": { $sum: 1 } } },
{ $match: { "count": { $gt: 1 } } },
{ $project: { "name": 1, "_id": 0 } },
{ $group: { "_id": null, "duplicateNames": { $push: "$name" } } },
{ $project: { "_id": 0, "duplicateNames": 1 } }
), function (err, result) {
if (result) {
console.log(result)
}
})
from above commented code it is giving me all id but now it is giving me null values and all the result json of 6000 with null value.
here is the field of data in collection:
My Schema is :
var mongoose = require('mongoose');
var uniqueValidator = require('mongoose-unique-validator');
var autoIncrement = require('mongoose-auto-increment');
var ModelRestaurant = new mongoose.Schema({
name: String,
ownerName: String, // to be removed by checking code
ownerID: Number,
ownerEmail: String, // to be removed by checking code
city: String,
zipCode: String,
image: [String],
restaurantType: String,
address: String,
landmark: String,
isAddedByCustomer: {
type: Boolean,
default: false
},
location: {
lat: String,
long: String
}
},
{
timestamps: true
});
ModelRestaurant.plugin(autoIncrement.plugin, 'Restaurants');
ModelRestaurant.plugin(uniqueValidator);
mongoose.model('Restaurants', ModelRestaurant);

Answer 1

The following code should print all the duplicates:
db.ModelRestaurant.aggregate([
{$group:{"_id":"$name","name":{$first:"$name"},"count":{$sum:1}}},
{$match:{"count":{$gt:1}}}
])