Kahraman kahramanX

#AJAX

What is AJAX

"AJAX an acronym for asynchronous JavaScript and XML is a group of interrelated web development techniques used on the client-side to create asynchronous web applications. With Ajax, web applications can send data to, and retrieve data from, a server asynchronously (in the background) without interfering with the display and behavior of the existing page. Data can be retrieved using the XMLHttpRequest object. Despite the name, the use of XML is not required (JSON is often used instead), and the requests do not need to be asynchronous." - wikipedia

AJAX with jQuery

jQuery provides a $.ajax() method with a set of options for sending requests and callback methods to handle responses.

Here is the most basic $.ajax() request that does not send any data. It will be handled by the post '/trips' route on the server. You can choose any of the http request verbs for the type parameter (get, post, put, delete)

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

-E: will describe the underlaying queries of the \ commands (cool for learning!)
-l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

Node.js MVC directory structure example.

├── app
│   ├── controllers
│   │   ├── admin
│   │   │   ├── posts.js
│   │   │   └── users.js
│   │   ├── posts.js
│ │ ├── session.js

	### the longest sql queries I've ever made in 2016
	### QUERY 2

	select table_keuangan.*, dzohir_target,dzohir_realisasi,dzohir_percentage,dzohir_satkeg
	from
	(
	select __is_kegiatan.description as nmitem, table_data.*,
	((anggaran_realisasi/anggaran_pagu)*100) as anggaran_percentage
	from __is_kegiatan
	join (

	const express = require('express')
	const app = express()
	const path = require('path')
	const fetch = require('node-fetch')
	const PORT = process.env.PORT \|\| 3000

	app.get('/api/user', (req, res) => {
	res.json({ name: 'Richard' });
	});