Mongo and node js a query to return with no duplicates , distinct

Question

How do we query in mongo where in the results would not have duplicates , I have tried using distinc but it does not seem to work.

Query

keystone.list('Customer').model.find().sort('name').where('vin').in([vin]).exec(

function (err, results) {

    if (err || !results.length) {
        return next(err);
    }
    .....    

Answer 1

keystone.list('Customer').model.find().distinct('customer_id')
  .where('fieldName', 'fieldValue')
  .exec(function(err, result) {
    //array of _ids
  });

Then pass all the ids in a $in query to get all the records.