@kos-ng-it-konsult/mongo-aggregator

This is a mongodb aggregator package for KOS NG IT Konsult.

Quick Start

Install

$ npm i --save @kos-ng-it-konsult/mongo-aggregator

Basic Usage

"use strict";

const mongoose = require('mongoose'); // run npm install --save mongoose
const lib = require('../index');

const db = mongoose.connect(`mongodb://127.0.0.1:27017/test`, {
    useFindAndModify: false,
    useNewUrlParser: true,
    useCreateIndex: true
});

const FormSchema = new mongoose.Schema({
    name: { type: String, required: true },
    code: { type: String, required: true }
});

const FormModel = mongoose.model("Form", FormSchema);

const StudentSchema = new mongoose.Schema({
    name: { type: String, required: true },
    age: { type: Number, required: true },
    gender: { type: String, required: true },
    form_id: { type: mongoose.Schema.Types.ObjectId, required: true, ref: "Form" }
});

const StudentModel = mongoose.model("Student", StudentSchema);

const aggregator = new lib().build();
aggregator
    .addStage('match', { name: { $in: [ 'femi' ] } })
    .addStage('lookup', {
        from: 'forms',
        localField: 'form_id',
        foreignField: '_id',
        as: 'form'
    })
    .addStage('unwind', '$form')
    .addStage('match', { 'form.name': { $in: [ 'form 1' ] } })
    .addStage('project', [
        '_id', 'name', 'age', 'gender',
        { name: 'form', value: '$form.name' }
    ]);

const dataAggregator = aggregator.output();

StudentModel.aggregate(dataAggregator).exec().then(data => {/*...*/}).catch(error => {/*...*/});

Running the Example

To run the example, first install mongoose using
$ npm install --save mongoose

Then run the sample command
$ node ./example/sample.js

Running Tests

Run
$ npm test