Introduction to Lowdb

Lowdb is a small, local JSON database powered by Lodash. It’s perfect for small projects, quick prototyping, or when you just need a simple, flat file database.

Installation

  npm install lowdb

Set Up

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

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

Basic CRUD Operations

Creating Records

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

  db.get('posts')
    .push({ id: 1, title: 'lowdb is awesome'})
    .write();

Reading Records

  const post = db.get('posts')
    .find({ id: 1 })
    .value();

Updating Records

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

Deleting Records

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

Advanced API Features

Setting Default Values

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

Using the Update Function

  db.update('count', n => n + 1)
    .write();

Using Write Function

  db.get('posts')
    .push({ id: 2, title: 'This is another post' })
    .write();

Full Application Example

Here’s a simple application example using Lowdb APIs

  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)
      .write();
    res.json(post);
  });

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

With these examples, you can now utilize Lowdb to enhance your web development projects. Experiment with the code snippets and create your own local JSON database applications effortlessly!

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