https://github.com/debitoor/mongo-map

When using mongoDB aggregation framework, this helper lets you make a lookup in a JS-map
https://github.com/debitoor/mongo-map

Last synced: 12 days ago
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When using mongoDB aggregation framework, this helper lets you make a lookup in a JS-map

• Host: GitHub
• URL: https://github.com/debitoor/mongo-map
• Owner: debitoor
• Created: 2015-04-21T14:10:09.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2015-04-23T09:26:26.000Z (over 9 years ago)
• Last Synced: 2024-11-01T21:05:28.422Z (16 days ago)
• Language: JavaScript
• Size: 156 KB
• Stars: 3
• Watchers: 46
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
mongo-map [![npm version](https://badge.fury.io/js/mongo-map.svg)](http://badge.fury.io/js/mongo-map) [![Build Status](https://travis-ci.org/e-conomic/mongo-map.svg?branch=master)](https://travis-ci.org/e-conomic/mongo-map) [![devDependency Status](https://david-dm.org/e-conomic/mongo-map/dev-status.svg)](https://david-dm.org/e-conomic/mongo-map#info=devDependencies)

=========

When working with [mongoDB Aggregation Framework](http://docs.mongodb.org/manual/aggregation) sometimes you need to transform a field based on plain js map object. Consider you have:

```javascript

var map = {

	forThisKey: 'retrun this value',

	thisKeyEqualsTo: 'something like this',

	andForThisOne: 'return some other string'

};

```

In regular js code you would do:

```javascript

var value = map[key];

```

This module helps you do the same inside aggregation framework pipeline.

	npm install mongo-map

	

## Requirements

- mongo 2.6.x or higher

## Usage

```javascript

var getInMap = require('mongo-map');

db.myCollection.aggregate([

	{ $project: {

		value: getInMap(map, '$key')

	} }

]);

```

Here `getInMap` expands your map object into a balanced search tree that aggregation framework uses to efficiently look up your key.

## License

[MIT](http://opensource.org/licenses/MIT)