Introduction to Lowdb

Lowdb is a small, local JSON database for Node, Electron, and the browser. It provides a simple API to manage data locally with no dependencies. In this article, we will explore the functionalities provided by Lowdb and their practical applications.

Getting Started

To get started with Lowdb, you need to install it first:

  
    npm install lowdb
  

Next, you should require it in your project:

  
    const low = require('lowdb')
    const FileSync = require('lowdb/adapters/FileSync')
    
    const adapter = new FileSync('db.json')
    const db = low(adapter)
  

Basic CRUD Operations

Lowdb makes CRUD (Create, Read, Update, Delete) operations simple and efficient. Here are some examples:

Create

  
    db.defaults({ posts: [], user: {} }).write()

    db.get('posts')
      .push({ id: 1, title: 'Lowdb is awesome', content: 'Exploring Lowdb...' })
      .write()
  

Read

  
    const post = db.get('posts')
                   .find({ id: 1 })
                   .value()
    
    console.log(post)
    // { id: 1, title: 'Lowdb is awesome', content: 'Exploring Lowdb...' }
  

Update

  
    db.get('posts')
      .find({ id: 1 })
      .assign({ title: 'Lowdb is super awesome!' })
      .write()
  

Delete

  
    db.get('posts')
      .remove({ id: 1 })
      .write()
  

Advanced Features

Lowdb also provides more advanced features for complex use-cases:

Using Lodash

  
    const _ = require('lodash')
    const customDb = db.__chain = lodash.chain
    
    const matchedPosts = db.get('posts')
                           .filter(post => post.title.includes('awesome'))
                           .value()

    console.log(matchedPosts)
  

Custom Adapters

  
    import low from 'lowdb';
    import LocalStorage from 'lowdb/adapters/LocalStorage'

    const adapter = new LocalStorage('db')
    const db = low(adapter)
  

Practical Application Example

Here is an example demonstrating a practical application of Lowdb:

  
    const express = require('express')
    const low = require('lowdb')
    const FileSync = require('lowdb/adapters/FileSync')

    const app = express()
    const adapter = new FileSync('db.json')
    const db = low(adapter)

    db.defaults({ posts: [] }).write()

    app.use(express.json())

    app.get('/posts', (req, res) => {
      const posts = db.get('posts').value()
      res.json(posts)
    })

    app.post('/posts', (req, res) => {
      const post = db.get('posts')
                    .push(req.body)
                    .last()
                    .assign({ id: Date.now() })
                    .write()
      res.status(201).json(post)
    })

    app.listen(3000, () => console.log('Server running on port 3000'))
  

In this example, we create an Express server that uses Lowdb to store and retrieve data locally.

Hope you find Lowdb as powerful and easy-to-use as we do!

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