Summing in mongodb

Question

I have this mongodb collection

   {
       "_id": "5ab93bd8bca5b3568ad93bc6",
       "name": "abc",
       "id":"1",
       "price": 300000,
       "__v": 0
   }
   {
       "_id": "5ab9d8bca5b334328ad934c1",
       "name": "cde",
       "id":"1",
       "price": 200000,
       "__v": 0
   }

I want to write a query to get the sum of the prices from all the documents from the collection. How could I do that?

Please use this route format. Regards

router.get('/values/:id', (req, res, next)=>{
    Value.count({ id: req.params.id }, function(err, value){
        res.json(value);
    });
});

Answer 1

I want to right a query to get the sum of price from all the documents from the collection

So why does your route require an ID?

Anyways, use aggregation particularly $sum.

router.get('/values/:id', (req, res, next) => {
    Value.aggregate([
        {
            $match: { id: req.params.id }
        },
        { 
            $group: {
                _id: "id",
                total: { $sum: "$price" }
            }
        }
    ], function (err, value){
        console.log(value);
    });
});

Answer 2

db.collectionName.aggregate([
 {$group:{"_id":{$sum:"$price"}}}
])