InternetProgramming/Lab3/node_modules/lowdb/examples/README.md
2023-12-15 14:42:22 +04:00

114 lines
2.1 KiB
Markdown

# Examples
## CLI
```js
const low = require('lowdb')
const FileSync = require('lowdb/adapters/FileSync')
const adapter = new FileSync('db.json')
const db = low(adapter)
db.defaults({ posts: [] })
.write()
const result = db.get('posts')
.push({ name: process.argv[2] })
.write()
console.log(result)
```
```sh
$ node cli.js hello
# [ { title: 'hello' } ]
```
## Browser
```js
import low from 'lowdb'
import LocalStorage from 'lowdb/adapters/LocalStorage'
const adapter = new LocalStorage('db')
const db = low(adapter)
db.defaults({ posts: [] })
.write()
// Data is automatically saved to localStorage
db.get('posts')
.push({ title: 'lowdb' })
.write()
```
## Server
Please __note__ that if you're developing a local server and don't expect to get concurrent requests, it's often easier to use `file-sync` storage, which is the default.
But if you need to avoid blocking requests, you can do so by using `file-async` storage.
```js
const express = require('express')
const low = require('lowdb')
const FileAsync = require('lowdb/adapters/FileAsync')
// Create server
const app = express()
// Routes
// GET /posts/:id
app.get('/posts/:id', (req, res) => {
const post = db.get('posts')
.find({ id: req.params.id })
.value()
res.send(post)
})
// POST /posts
app.post('/posts', (req, res) => {
db.get('posts')
.push(req.body)
.last()
.assign({ id: Date.now() })
.write()
.then(post => res.send(post))
})
// Create database instance and start server
const adapter = new FileAsync('db.json')
low(adapter)
.then(db => {
db.defaults({ posts: [] })
.write()
})
.then(() => {
app.listen(3000, () => console.log('listening on port 3000')
})
```
## In-memory
With this adapter, calling `write` will do nothing. One use case for this adapter can be for tests.
```js
const fs = require('fs')
const low = require('low')
const FileSync = require('low/adapters/FileSync')
const Memory = require('low/adapters/Memory')
const db = low(
process.env.NODE_ENV === 'test'
? new Memory()
: new FileSync('db.json')
)
db.defaults({ posts: [] })
.write()
db.get('posts')
.push({ title: 'lowdb' })
.write()
```