Unique Random Docs

Allows to fetching random absolutely unique docs from MongoDB collection

Problem

Starting with the 3.2 release of MongoDB, you can get N random docs from a collection using the $sample aggregation pipeline operator:

db.mycoll.aggregate([{ $sample: { size: 14 } }])

problem is that docs you get can be not unique, and can be duplicated

Solving

To solve this problem, you can use this package. It's recursive filtering all you fetching docs, and returns only unique ones!

Usage

Your need to install mongoose in your project

npm i mongoose

then

npm i unique-random-docs

then in your module where you want get random unique docs from colection:

const getUniqeRandomDocuments = require('unique-random-docs')
const SomeItemsSchema = require("../models/items");

and a code as example:

exports.aggregate = async function (req, res) {
  try {
  const response = await getUniqeRandomDocuments('Items', SomeItemsSchema, 5 );
  res.send(response);
} catch (err) {
  console.log(err)
}

getUniqeRandomDocuments(collection, schema, size, set)

• collection - represent collection name, in this case 'Items'
• schema - schema for collection, in this case exported from mongoose SomeItemsSchema
• size - counts a number of unique docs that you want to take, we get 5.
• set - $set (aggregation) optional paramater, outputs documents that contain all existing fields from the input documents, for specific search.

License

MIT

Free Software, Hell Yeah!