Moongoose aggregate $match does not match id's

user_5083909 0
Viewed 42066

I want to show products by ids (56e641d4864e5b780bb992c6 and 56e65504a323ee0812e511f2) and show price after subtracted by discount if available.

I can count the final price using aggregate, but this return all document in a collection, how to make it return only the matches ids

"_id" : ObjectId("56e641d4864e5b780bb992c6"), 
"title" : "Keyboard", 
"discount" : NumberInt(10),
"price" : NumberInt(1000)

"_id" : ObjectId("56e65504a323ee0812e511f2"), 
"title" : "Mouse", 
"discount" : NumberInt(0),
"price" : NumberInt(1000)

"_id" : ObjectId("56d90714a48d2eb40cc601a5"), 
"title" : "Speaker", 
"discount" : NumberInt(10),
"price" : NumberInt(1000)

this is my query

productModel.aggregate([
        {
            $project: {
                title   : 1,
                price: {
                    $cond: {
                        if: {$gt: ["$discount", 0]}, then: {$subtract: ["$price", {$divide: [{$multiply: ["$price", "$discount"]}, 100]}]}, else: "$price"
                    }

                }
            }
        }
    ], function(err, docs){
        if (err){
            console.log(err)
        }else{
            console.log(docs)
        }
    })

and if i add this $in query, it returns empty array 

productModel.aggregate([
            {
                $match: {_id: {$in: ids}}
            },
            {
                $project: {
                    title   : 1,
                    price: {
                        $cond: {
                            if: {$gt: ["$discount", 0]}, then: {$subtract: ["$price", {$divide: [{$multiply: ["$price", "$discount"]}, 100]}]}, else: "$price"
                    }

                }
            }
        }
    ], function(err, docs){
        if (err){
            console.log(err)
        }else{
            console.log(docs)
        }
    })
mongoose aggregation-framework mongodb-query mongodb
5 Answers

  1. In the mongoose , it work fine with find({_id:'606c1ceb362b366a841171dc'})

  2. But while using the aggregate function we have to use the mongoose object to convert the _id as object eg.

$match: { "_id": mongoose.Types.ObjectId("606c1ceb362b366a841171dc") }

This will work fine.

user_129807260

You can simply convert your id to

 let id = mongoose.Types.ObjectId(req.query.id);

and then match

 { $match: { _id: id } },
user_140620420

instead of:

$match: { _id: "6230415bf48824667a417d56" }

use:

$match: { _id: ObjectId("6230415bf48824667a417d56") }
user_63467850

Use this

$match: { $in : [ {_id: mongoose.Types.ObjectId("56e641d4864e5b780bb992c6 ")}, {_id: mongoose.Types.ObjectId("56e65504a323ee0812e511f2")}] }

Because Mongoose autocasts string values for ObjectId into their correct type in regular queries, but this does not happen in the aggregation pipeline. So we need to define ObjectId cast in pipeline queries.

user_26429280
Related