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Nodejs Angular 12 Upload File/Download File from PostgreSQL – with Node.js/Express RestAPIs example – using Multer + Sequelize ORM - ozenero

https://ozenero.com/nodejs-angular-12-upload-file-download-file-from-postgresql-with-node-js-express-restapis-example-using-multer-sequelize-orm

In the tutorial, we show how to upload files, download files from Angular 12 Client to PostgreSQL with Node.js RestAPIs server using Multer middleware and Sequelize ORM.

 

Related posts:
Node.js/Express RestAPIs server – Angular 12 Upload/Download Files – Multer + Bootstrap
Node.js/Express – PostgreSQL example – Upload File/Download File – Multer + Sequelize CRUD

 

 

Technologies

  • Angular 12
  • RxJS 6
  • Bootstrap 4
  • Visual Studio Code – version 1.24.0
  • Nodejs – v8.11.3
  • Multer
  • Sequelize
  • PostgreSQL

Overview

We create 2 projects: {Node.js, Angular}

Node.js RestAPIs

Project structure ->

angular-6-httpclient-postgresql-example-node-js-express-upload-file-download-files-sequelize-orm-crud-multer + node-js-project-structure

 

– Node.js project exposes RestAPIs to upload/download files:

  • router.post('/api/file/upload', upload.single("file"), fileWorker.uploadFile);
  • router.get('/api/file/info', fileWorker.listAllFiles);
  • router.get('/api/file/:id', fileWorker.downloadFile);

Configure cross-origin for Angular-Client which running at port: 4200.


const cors = require('cors')
const corsOptions = {
  origin: 'http://localhost:4200',
  optionsSuccessStatus: 200
}
app.use(cors(corsOptions))

Upload File ->

To upload MultipartFile, we use Multer middleware. Setup Mutter-Memory storage:


const multer = require('multer');
 
var storage = multer.memoryStorage()
var upload = multer({storage: storage});

 

How to upload file and save it to PostgreSQL?

– Router to handle uploaded-file from multipart/form-data:


const fileWorker = require('../controllers/file.controller.js');
...
 
app.post('/api/file/upload', upload.single("file"), (req, res) => { 
	/*
		to do
	*/
});

– Now, uploaded file is stored in req.file.buffer. Save it to PostgreSQL with Sequelize ORM:


File = sequelize.define('file', {
	  type: {
		type: Sequelize.STRING
	  },
	  name: {
		type: Sequelize.STRING
	  },
	  data: {
		type: Sequelize.BLOB('long')
	  }
});
 
...
 
(req, res) => {
	File.create({
		type: req.file.mimetype,
		name: req.file.originalname,
		data: req.file.buffer
	}).then(() => {
		res.json({msg: 'File uploaded successfully! -> filename = ' + req.file.originalname});
	})
}

Download File ->

For getting file from PostgreSQL then sending to client, we use Squelize ORM and stream module as below code:


var stream = require('stream');
 
...
File.findById(req.params.id).then(file => {
	var fileContents = Buffer.from(file.data, "base64");
	var readStream = new stream.PassThrough();
	readStream.end(fileContents);
	
	res.set('Content-disposition', 'attachment; filename=' + file.name);
	res.set('Content-Type', file.type);
 
	readStream.pipe(res);
})

Angular 12 Client

Project structure ->

 

  • upload-file.service provides methods: push File to Storage and get Files.
  • list-upload.component gets and displays list of Files.
  • form-upload.component helps upload File.
  • details-upload.component is detail for each item in list of Files.

angular-6-httpclient-postgresql-example-node-js-express-upload-file-download-files-sequelize-orm-crud-multer + angular-component-overviews

PostgreSQL’s records:

angular-6-httpclient-postgresql-example-node-js-express-upload-file-download-files-sequelize-orm-crud-multer + postgresql-records

Practice

Node.js RestAPIs

Setting up NodeJs/Express project

Create a folder Node.js-Express-Upload-Download-Files-PostgreSQL:


mkdir Node.js-Express-Upload-Download-Files-PostgreSQL
cd Node.js-Express-Upload-Download-Files-PostgreSQL

Then init NodeJS project:


Node.js-Express-Upload-Download-Files-PostgreSQL>npm init
This utility will walk you through creating a package.json file.
It only covers the most common items, and tries to guess sensible defaults.
 
See `npm help json` for definitive documentation on these fields
and exactly what they do.
 
Use `npm install ` afterwards to install a package and
save it as a dependency in the package.json file.
 
Press ^C at any time to quit.
package name: (nodejs-express-upload-file-postgresql)
version: (1.0.0)
description: Building a Node.js/Express RestAPIs that upload/download files to PostgreSQL database using Multer middleware, Sequelize ORM
entry point: (index.js) server.js
test command:
git repository:
keywords: NodeJS, Express, PostgreSQL, Multer, Sequelize
author: ozenero.com
license: (ISC)
About to write to C:\nodejs\Node.js-Express-Upload-Download-Files-PostgreSQL\package.json:
 
{
  "name": "nodejs-express-upload-file-postgresql",
  "version": "1.0.0",
  "description": "Building a Node.js/Express RestAPIs that upload/download files to PostgreSQL database using Multer middleware, Sequelize ORM",
  "main": "server.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [
    "Node.js",
    "Express",
    "PostgreSQL", 
    "Multer",
    "Sequelize"
  ],
  "author": "ozenero.com",
  "license": "ISC"
}
 
 
Is this ok? (yes) yes

We need express, multer and cors modules.
– Express is one of the most popular web frameworks for NodeJs which is built on top of Node.js http module, and adds support for routing, middleware, view system etc.
– Multer is a node.js middleware for handling multipart/form-data , which is primarily used for uploading files.
– Cors: a mechanism that uses HTTP headers to tell a browser to let a web application running at one origin (domain) have permission to access selected resources from a server at a different origin.

-> Install Express, Multer, Sequelize, PostgreSQL, Cors:


npm install express multer sequelize pg pg-hstore cors --save

-> see package.json file:

What is GEEK

Buddha Community

Nodejs Angular 12 Upload File/Download File from PostgreSQL – with Node.js/Express RestAPIs example – using Multer + Sequelize ORM - ozenero

Angular 8 Nodejs PostgreSQL CRUD Example - using Express RestAPIs + Sequelize

https://loizenai.com/angular-8-nodejs-postgresql-crud-example/

In the tutorial, I introduce how to build an Angular 8 Nodejs PostgreSQL CRUD Example RestAPIs project with the help of Express Web Framework and Sequelize ORM for POST/GET/PUT/DELETE requests with step by step coding examples.

Fullstack Architecture Angular 8 PostgreSQL Nodejs CRUD RestAPIs Application

Architecture Overview Nodejs Express Sequelize PostgreSQL CRUD RestAPIs Application

Nodejs CRUD Application Project Structure

Angular 8 Application Architecture CRUD Nodejs RestAPIs

Angular 8 CRUD Application – Update data successfully to PostgreSQL database

#angular #nodejs #postgresql #express #restapi #sequelize

NodeJS/Express - RestAPI to Upload Multipart File to MySQL using Multer + Sequelize ORM

https://grokonez.com/node-js/nodejs-express-restapi-to-upload-multipart-file-to-mysql-using-multer-sequelize-orm

NodeJS/Express – RestAPI to Upload Multipart File to MySQL using Multer + Sequelize ORM

In the tutorial, we show how to build a NodeJS/Express RestAPI to upload Multipart Files/Images to MySQL using Multer middleware and Sequelize ORM.

Related posts:

Goal

Prerequisites

- NodeJS – Save File/Image to MySQL by Sequelize with BLOB type - Multer – Build RestAPI to upload a MultipartFile to NodeJS/Express

Objective

In the tutorial, we create a NodeJS project that build RestAPI to upload files/images to MySQL database, see below project structure:

/NodeJS-Express-Multer-Upload-MultipartFile-Sequelize-MySQL
	/app
		/config
			db.config.js
			env.js
			upload.config.js
		/controllers
			upload.controller.js
		/models
			img.model.js
		/routers
			upload.router.js
	/node_modules
	/resources
		/static
			/assets
				/uploads /* the folder is used to store uploaded files/images in disk*/
				/tmp /* the folder is used to store files/images which are retrieved from MySQL database*/
	package.json
	server.js

Using PostMan to make a POST request:

NodeJS-Express-Multer-Upload-MultipartFile-MySQL-Sequelize-upload-from-postman

-> result:

NodeJS-Express-Multer-Upload-MultipartFile-MySQL-Sequelize-saving-to-mysql table

Practice

Setting up NodeJS/Express project

Create a folder 'NodeJS-Express-Multer-Upload-MultipartFile-Sequelize-MySQL':

More at:

https://grokonez.com/node-js/nodejs-express-restapi-to-upload-multipart-file-to-mysql-using-multer-sequelize-orm

NodeJS/Express – RestAPI to Upload Multipart File to MySQL using Multer + Sequelize ORM

#node #express #multer #restapi #sequelize

Node.js/Express - PostgreSQL example - Upload File/Download File - Multer + Sequelize CRUD

https://ozenero.com/node-js-express-rest-api-postgresql-example-upload-file-download-file-multer-sequelize-crud

Node.js/Express – PostgreSQL example – Upload File/Download File – Multer + Sequelize CRUD

In the tutorial, we show how to build a Node.js/Express RestAPIs to Upload Files/Download Files to PostgreSQL using Multer middleware and Sequelize ORM.

Related posts:

Technologies

  • Node.js
  • Express
  • Multer
  • Sequelize
  • PostgreSQL

Goal

We create Node.js project as below: nodejs-express-restapis-multer-upload-files-download-files-sequelize-postgresql + nodejs-project

Expose 3 RestAPIs:

  • router.post('/api/file/upload', upload.single("file"), fileWorker.uploadFile);
  • router.get('/api/file/info', fileWorker.listAllFiles);
  • router.get('/api/file/:id', fileWorker.downloadFile);

Upload file:

nodejs-express-restapis-multer-upload-files-download-files-sequelize-postgresql + post-request-upload-file

-> PostgreSQL’s records:

nodejs-express-restapis-multer-upload-files-download-files-sequelize-postgresql + postgrsql-records

Download file:

nodejs-express-restapis-multer-upload-files-download-files-sequelize-postgresql + get-file

Practice

Setting up NodeJs/Express project

Create a folder Node.js-Express-Upload-Download-Files-PostgreSQL:

More at:

https://ozenero.com/node-js-express-rest-api-postgresql-example-upload-file-download-file-multer-sequelize-crud

Node.js/Express – PostgreSQL example – Upload File/Download File – Multer + Sequelize CRUD

#nodejs #crud #postgresql #sequelize #multer

NBB: Ad-hoc CLJS Scripting on Node.js

Nbb

Not babashka. Node.js babashka!?

Ad-hoc CLJS scripting on Node.js.

Status

Experimental. Please report issues here.

Goals and features

Nbb's main goal is to make it easy to get started with ad hoc CLJS scripting on Node.js.

Additional goals and features are:

  • Fast startup without relying on a custom version of Node.js.
  • Small artifact (current size is around 1.2MB).
  • First class macros.
  • Support building small TUI apps using Reagent.
  • Complement babashka with libraries from the Node.js ecosystem.

Requirements

Nbb requires Node.js v12 or newer.

How does this tool work?

CLJS code is evaluated through SCI, the same interpreter that powers babashka. Because SCI works with advanced compilation, the bundle size, especially when combined with other dependencies, is smaller than what you get with self-hosted CLJS. That makes startup faster. The trade-off is that execution is less performant and that only a subset of CLJS is available (e.g. no deftype, yet).

Usage

Install nbb from NPM:

$ npm install nbb -g

Omit -g for a local install.

Try out an expression:

$ nbb -e '(+ 1 2 3)'
6

And then install some other NPM libraries to use in the script. E.g.:

$ npm install csv-parse shelljs zx

Create a script which uses the NPM libraries:

(ns script
  (:require ["csv-parse/lib/sync$default" :as csv-parse]
            ["fs" :as fs]
            ["path" :as path]
            ["shelljs$default" :as sh]
            ["term-size$default" :as term-size]
            ["zx$default" :as zx]
            ["zx$fs" :as zxfs]
            [nbb.core :refer [*file*]]))

(prn (path/resolve "."))

(prn (term-size))

(println (count (str (fs/readFileSync *file*))))

(prn (sh/ls "."))

(prn (csv-parse "foo,bar"))

(prn (zxfs/existsSync *file*))

(zx/$ #js ["ls"])

Call the script:

$ nbb script.cljs
"/private/tmp/test-script"
#js {:columns 216, :rows 47}
510
#js ["node_modules" "package-lock.json" "package.json" "script.cljs"]
#js [#js ["foo" "bar"]]
true
$ ls
node_modules
package-lock.json
package.json
script.cljs

Macros

Nbb has first class support for macros: you can define them right inside your .cljs file, like you are used to from JVM Clojure. Consider the plet macro to make working with promises more palatable:

(defmacro plet
  [bindings & body]
  (let [binding-pairs (reverse (partition 2 bindings))
        body (cons 'do body)]
    (reduce (fn [body [sym expr]]
              (let [expr (list '.resolve 'js/Promise expr)]
                (list '.then expr (list 'clojure.core/fn (vector sym)
                                        body))))
            body
            binding-pairs)))

Using this macro we can look async code more like sync code. Consider this puppeteer example:

(-> (.launch puppeteer)
      (.then (fn [browser]
               (-> (.newPage browser)
                   (.then (fn [page]
                            (-> (.goto page "https://clojure.org")
                                (.then #(.screenshot page #js{:path "screenshot.png"}))
                                (.catch #(js/console.log %))
                                (.then #(.close browser)))))))))

Using plet this becomes:

(plet [browser (.launch puppeteer)
       page (.newPage browser)
       _ (.goto page "https://clojure.org")
       _ (-> (.screenshot page #js{:path "screenshot.png"})
             (.catch #(js/console.log %)))]
      (.close browser))

See the puppeteer example for the full code.

Since v0.0.36, nbb includes promesa which is a library to deal with promises. The above plet macro is similar to promesa.core/let.

Startup time

$ time nbb -e '(+ 1 2 3)'
6
nbb -e '(+ 1 2 3)'   0.17s  user 0.02s system 109% cpu 0.168 total

The baseline startup time for a script is about 170ms seconds on my laptop. When invoked via npx this adds another 300ms or so, so for faster startup, either use a globally installed nbb or use $(npm bin)/nbb script.cljs to bypass npx.

Dependencies

NPM dependencies

Nbb does not depend on any NPM dependencies. All NPM libraries loaded by a script are resolved relative to that script. When using the Reagent module, React is resolved in the same way as any other NPM library.

Classpath

To load .cljs files from local paths or dependencies, you can use the --classpath argument. The current dir is added to the classpath automatically. So if there is a file foo/bar.cljs relative to your current dir, then you can load it via (:require [foo.bar :as fb]). Note that nbb uses the same naming conventions for namespaces and directories as other Clojure tools: foo-bar in the namespace name becomes foo_bar in the directory name.

To load dependencies from the Clojure ecosystem, you can use the Clojure CLI or babashka to download them and produce a classpath:

$ classpath="$(clojure -A:nbb -Spath -Sdeps '{:aliases {:nbb {:replace-deps {com.github.seancorfield/honeysql {:git/tag "v2.0.0-rc5" :git/sha "01c3a55"}}}}}')"

and then feed it to the --classpath argument:

$ nbb --classpath "$classpath" -e "(require '[honey.sql :as sql]) (sql/format {:select :foo :from :bar :where [:= :baz 2]})"
["SELECT foo FROM bar WHERE baz = ?" 2]

Currently nbb only reads from directories, not jar files, so you are encouraged to use git libs. Support for .jar files will be added later.

Current file

The name of the file that is currently being executed is available via nbb.core/*file* or on the metadata of vars:

(ns foo
  (:require [nbb.core :refer [*file*]]))

(prn *file*) ;; "/private/tmp/foo.cljs"

(defn f [])
(prn (:file (meta #'f))) ;; "/private/tmp/foo.cljs"

Reagent

Nbb includes reagent.core which will be lazily loaded when required. You can use this together with ink to create a TUI application:

$ npm install ink

ink-demo.cljs:

(ns ink-demo
  (:require ["ink" :refer [render Text]]
            [reagent.core :as r]))

(defonce state (r/atom 0))

(doseq [n (range 1 11)]
  (js/setTimeout #(swap! state inc) (* n 500)))

(defn hello []
  [:> Text {:color "green"} "Hello, world! " @state])

(render (r/as-element [hello]))

Promesa

Working with callbacks and promises can become tedious. Since nbb v0.0.36 the promesa.core namespace is included with the let and do! macros. An example:

(ns prom
  (:require [promesa.core :as p]))

(defn sleep [ms]
  (js/Promise.
   (fn [resolve _]
     (js/setTimeout resolve ms))))

(defn do-stuff
  []
  (p/do!
   (println "Doing stuff which takes a while")
   (sleep 1000)
   1))

(p/let [a (do-stuff)
        b (inc a)
        c (do-stuff)
        d (+ b c)]
  (prn d))
$ nbb prom.cljs
Doing stuff which takes a while
Doing stuff which takes a while
3

Also see API docs.

Js-interop

Since nbb v0.0.75 applied-science/js-interop is available:

(ns example
  (:require [applied-science.js-interop :as j]))

(def o (j/lit {:a 1 :b 2 :c {:d 1}}))

(prn (j/select-keys o [:a :b])) ;; #js {:a 1, :b 2}
(prn (j/get-in o [:c :d])) ;; 1

Most of this library is supported in nbb, except the following:

  • destructuring using :syms
  • property access using .-x notation. In nbb, you must use keywords.

See the example of what is currently supported.

Examples

See the examples directory for small examples.

Also check out these projects built with nbb:

API

See API documentation.

Migrating to shadow-cljs

See this gist on how to convert an nbb script or project to shadow-cljs.

Build

Prequisites:

  • babashka >= 0.4.0
  • Clojure CLI >= 1.10.3.933
  • Node.js 16.5.0 (lower version may work, but this is the one I used to build)

To build:

  • Clone and cd into this repo
  • bb release

Run bb tasks for more project-related tasks.

Download Details:
Author: borkdude
Download Link: Download The Source Code
Official Website: https://github.com/borkdude/nbb 
License: EPL-1.0

#node #javascript

Node.js/Express - PostgreSQL example - Upload File/Download File - Multer

https://grokonez.com/node-js/sequelize/node-js-express-rest-api-postgresql-example-upload-file-download-file-multer-sequelize-crud

Node.js/Express – PostgreSQL example – Upload File/Download File – Multer + Sequelize CRUD

In the tutorial, we show how to build a Node.js/Express RestAPIs to Upload Files/Download Files to PostgreSQL using Multer middleware and Sequelize ORM.

Related posts:

Technologies

  • Node.js
  • Express
  • Multer
  • Sequelize
  • PostgreSQL

Goal

We create Node.js project as below: nodejs-express-restapis-multer-upload-files-download-files-sequelize-postgresql + nodejs-project

Expose 3 RestAPIs:

  • router.post('/api/file/upload', upload.single("file"), fileWorker.uploadFile);
  • router.get('/api/file/info', fileWorker.listAllFiles);
  • router.get('/api/file/:id', fileWorker.downloadFile);

Upload file:

nodejs-express-restapis-multer-upload-files-download-files-sequelize-postgresql + post-request-upload-file

-> PostgreSQL’s records:

nodejs-express-restapis-multer-upload-files-download-files-sequelize-postgresql + postgrsql-records

Download file:

nodejs-express-restapis-multer-upload-files-download-files-sequelize-postgresql + get-file

Practice

Setting up NodeJs/Express project

Create a folder Node.js-Express-Upload-Download-Files-PostgreSQL:

mkdir Node.js-Express-Upload-Download-Files-PostgreSQL
cd Node.js-Express-Upload-Download-Files-PostgreSQL

More:

https://grokonez.com/node-js/sequelize/node-js-express-rest-api-postgresql-example-upload-file-download-file-multer-sequelize-crud

Node.js/Express – PostgreSQL example – Upload File/Download File – Multer + Sequelize CRUD

#nodejs #sequelize #mysql #crud #postgresql #upload-file