Querying populated fields return empty array

Describe the bug When you query a subdocument that has been populated, the query returns empty array.

To Reproduce Steps to reproduce the behavior: 1.- Create a Schema with populated fields.

const ProjectSchema = new mongoose.Schema(
    {
        name: {
            en: {
                type: String,
                required: true,
            },
            es: {
                type: String,
                required: true,
            },
        },
        maker: { type: ObjectId, ref: 'Maker' }
}

2.- Create an endpoint to retrieve items from the new model using paginate with a filter using a populated field:

const getItemsFromDB = async (req, query) => {
const options = {
        sort: 'createdAt',
        lean: true,
        1,
        5,
         { path: 'maker', select: 'name' },
    }
    return new Promise((resolve, reject) => {
        model.paginate(query, options, (err, items) => {
            if (err) {
                reject(buildErrObject(422, err.message))
            }
            resolve(cleanPaginationID(items))
        })
    })
}

3.- Call the endpoint querying the populated field:

{{server}}/projects?filter={"maker.name":"Ocean Sentry"}&page=1&limit=2&sort=name&order=-1

4.- Get an empty array in the results:

{
    "docs": [],
    "totalDocs": 0,
    "limit": 2,
    "hasPrevPage": false,
    "hasNextPage": false,
    "page": 1,
    "totalPages": 1,
    "pagingCounter": 1,
    "prevPage": null,
    "nextPage": null
}

Expected behavior An array containing the results. If you query for a field with subdocuments (not populated) it works correctly.

[aravindnc]

@ramoncardena Great. Cool. You have to edit the write-up there is a typo,

for more complex cases mongoose-aggregate-paginate-v2 is the right choice.

[otaviobps]

Hi @ramoncardena how did you do your query? I’m getting an empty array when I try to query a field of the populated collection:

const myAggregate = Order.aggregate([
      {
        $lookup: {
          from: "users",
          localField: "user",
          foreignField: "_id",
          as: "user"
        }
      },
      {
        $unwind: "$user"
      },
      {
        $match: { user: { firstName: "Francisco" } }
      }
    ]);

If I skip the query, I get the fields populated, so I’m sure is something with the query. I’m using the mongoose-aggregate-paginate-v2, however I can’t query from a populated field.

Thanks!