CODEWITHSUNDEEP
node.jsmongodbmongooseaggregation-framework
Erik
Erik

Reputation: 14750

How to count aggregate query?

I'm building pagination with mongoose/nodejs application and have the following code:

var Query = Model.find(   
  "location": {
     "$geoWithin": {
        "$box": [
           [165.8694369, -52.61941849999999],
           [175.831536, -29.2313419]
         ]
     }
  }
});

// Get count of documents
return Query.count(function (err, totalCount) {
    if (err) throw err;

    // Get paginated list
    return Query.
          find().
          skip(skip).
          limit(limit).
          exec(function (err, results) {
             if (err) throw err;

             // return result 
          });

In the preceding code I get totalCount to build pagination on client-side and it works fine. But now I need to use aggregate instead find and trying the following:

// Construct pipeline
var pipeline = [{
   "$geoNear": {
      "near": [165.8694369, -52.61941849999999],
      "distanceField": "distance"
    }
}];

var Query = adModel.aggregate(pipeline);

// Get count of documents
return Query.count(function (err, totalCount) {
    if (err) throw err;

But unfortunately I get the error count() method does not exists. How could I total count of documents with aggregation framework?

Upvotes: 0

Views: 1558

Answers (1)

Valerio Barrila
Valerio Barrila

Reputation: 191

The problem is that Model.aggregate doesn't return a Query object that's why the count method does not exists.

Anyway since it returns a promise you can count your docs like this:

adModel.aggregate(pipeline).then(function (docs) {
    console.log(docs.length);
});

and if you don't like promises you can still pass a callback:

adModel.aggregate(pipeline, function (err, docs) {
    console.log(docs.length);
});

Upvotes: 2

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