What is lokijs?
LokiJS is an in-memory database that prioritizes performance and simplicity. It is written in JavaScript and can be used in web browsers, Node.js, and Cordova/PhoneGap applications. It offers a powerful query system and supports indexing for fast lookups.
What are lokijs's main functionalities?
In-memory database
LokiJS allows you to create an in-memory database, add collections, and insert documents.
const loki = require('lokijs');
const db = new loki('example.db');
const users = db.addCollection('users');
users.insert({ name: 'Odin', age: 1000 });
users.insert({ name: 'Thor', age: 30 });
Powerful query system
You can query the database using a MongoDB-like query syntax to retrieve data based on complex criteria.
const elderlyGods = users.find({ age: { '$gt': 500 } });
Indexing for fast lookups
LokiJS supports indexing of collections to enable faster query response times, especially beneficial for large datasets.
users.ensureIndex('age');
const youngGods = users.find({ age: { '$lte': 100 } });
Persistence adapters
LokiJS can be configured to use various persistence adapters, allowing you to save the database state to a file, local storage, or other storage systems.
const lokiFsAdapter = require('lokijs/src/loki-fs-structured-adapter');
const adapter = new lokiFsAdapter();
const db = new loki('example.db', { adapter: adapter });
Changes API
The Changes API allows you to listen for changes in the database, which can be used for syncing with a remote database or triggering other actions.
db.on('changes', function(changes) {
console.log('Database changes:', changes);
});
users.insert({ name: 'Loki', age: 1042 });
Other packages similar to lokijs
nedb
NeDB is another lightweight JavaScript database, similar to LokiJS, that works both in Node.js and the browser. It also offers in-memory storage and has a MongoDB-like API. However, NeDB is no longer actively maintained.
pouchdb
PouchDB is a database that runs in the browser or in Node.js and is designed to sync with CouchDB. It offers similar query capabilities to LokiJS but focuses more on synchronization and offline-first applications.
rxdb
RxDB is a reactive database for JavaScript applications, which can be used in browsers, Node.js, and hybrid apps. It is built on top of PouchDB and offers real-time synchronization and event-driven data flows, which is different from LokiJS's approach.
lowdb
LowDB is a small local JSON database powered by Lodash, suitable for small projects (Node, Electron, and the browser). It is simpler than LokiJS and does not offer in-memory storage, but it is easy to use for small datasets and simple applications.
LokiJS
Overview
LokiJS is a document oriented database written in javascript, published under MIT License.
Its purpose is to store javascript objects as documents in a nosql fashion and retrieve them with a similar mechanism.
Runs in node (including cordova/phonegap and node-webkit), nativescript and the browser.
LokiJS is ideal for the following scenarios:
- client-side in-memory db is ideal (e.g., a session store)
- performance critical applications
- cordova/phonegap mobile apps where you can leverage the power of javascript and avoid interacting with native databases
- data sets loaded into a browser page and synchronised at the end of the work session
- node-webkit desktop apps
- nativescript mobile apps that mix the power and ubiquity of javascript with native performance and ui
LokiJS supports indexing and views and achieves high-performance through maintaining unique and binary indexes (indices) for data.
Demo
The following demos are available:
- Sandbox / Playground
- a node-webkit small demo in the folder demos/desktop_app. You can launch it by running
/path/to/nw demos/desktop_app/
Wiki
Example usage can be found on the wiki
Main Features
- Fast performance NoSQL in-memory database, collections with unique index (1.1M ops/s) and binary-index (500k ops/s)
- Runs in multiple environments (browser, node, nativescript)
- Dynamic Views for fast access of data subsets
- Built-in persistence adapters, and the ability to support user-defined ones
- Changes API
- Joins
Current state
LokiJS is at version 1.3 [Eostre].
As LokiJS is written in JavaScript it can be run on any environment supporting JavaScript such as browsers, node.js/node-webkit, nativescript mobile framework and hybrid mobile apps (such as phonegap/cordova).
Made by @techfort, with the precious help of Dave Easterday.
Leave a tip or give us a star if you find LokiJS useful!
Installation
For browser environments you simply need the lokijs.js file contained in src/
You can use bower to install lokijs with bower install lokijs
For node and nativescript environments you can install through npm install lokijs
.
Roadmap
- exactIndex
- key-value datastore
- MRU cache
- MongoDB API compatibility
- server standalone (tcp and http servers and clients)
- replication and horizontal scaling
Contact
For help / enquiries contact joe.minichino@gmail.com
Commercial Support
For commercial support contact info.techfort@gmail.com
License
Copyright (c) 2015 TechFort joe.minichino@gmail.com
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.