justsml

Postgres Cheatsheet

This is a collection of the most common commands I run while administering Postgres databases. The variables shown between the open and closed tags, "<" and ">", should be replaced with a name you choose. Postgres has multiple shortcut functions, starting with a forward slash, "". Any SQL command that is not a shortcut, must end with a semicolon, ";". You can use the keyboard UP and DOWN keys to scroll the history of previous commands you've run.

Setup

installation, Ubuntu

http://www.postgresql.org/download/linux/ubuntu/ https://help.ubuntu.com/community/PostgreSQL

justsml

<input type='file' multiple class='files' name='files' />

justsml

// OPTION #1: no temp streamProcessor var
fetch(...)
  .then(progressHelper(console.log))

// ⚠️ OR️ ️⚠️

// OPTION #2: define a `streamProcessor` to hold our console logger
const streamProcessor = progressHelper(console.log)
fetch(...)
  .then(streamProcessor)

justsml

const getBlob = url => fetch(url)
  .then(progressHelper(console.log)) // progressHelper used inside the .then()
  .then(response => response.blob())

justsml

const progressHelper = require('./progressHelper.js')

const handler = ({loaded, total}) => {
  console.log(`Downloaded ${loaded} of ${total}`)
}
// handler args: ({ loaded = Kb, total = 0-100% })
const streamProcessor = progressHelper(handler)
// => streamProcessor is a function for use with the response _stream_

justsml

// The progressHelper could be inline w/ .then() below...
const streamProcessor = progressHelper(console.log)

fetch('https://fetch-progress.anthum.com/20kbps/images/sunrise-progressive.jpg')
  .then(streamProcessor) // note: NO parentheses because `.then` needs to get a function
  .then(response => response.blob())
  .then(blobData => {
    // ... set as base64 on an <img src="base64...">
  })

justsml

postFile('http://example.com/api/v1/users', 'input[type="file"].files')
  .then(data => console.log(data))

function postFile(url, fileSelector) {
  const formData = new FormData()
  const fileFields = document.querySelectorAll(fileSelector)

  // Add all files to formData
  Array.prototype.forEach.call(fileFields.files, f => formData.append('files', f))
  // Alternatively for PHPeeps, use `files[]` for the name to support arrays

justsml

postFile('http://example.com/api/v1/users', 'input[type="file"].avatar')
  .then(data => console.log(data))

function postFile(url, fileSelector) {
  const formData = new FormData()
  const fileField = document.querySelector(fileSelector)

  formData.append('username', 'abc123')
  formData.append('avatar', fileField.files[0])

justsml

postFormData('http://example.com/api/v1/users', {user: 'Mary'})
  .then(data => console.log(data))

function postFormData(url, data) {
  return fetch(url, {
    method: 'POST', // 'GET', 'PUT', 'DELETE', etc.
    body: new URLSearchParams(data),
    headers: new Headers({
      'Content-type': 'application/x-www-form-urlencoded; charset=UTF-8'
    })

justsml

postFormData('http://example.com/api/v1/users', {user: 'Mary'})
  .then(data => console.log(data))

function postFormData(url, data) {
  return fetch(url, {
    method: 'POST', // 'GET', 'PUT', 'DELETE', etc.
    body: new URLSearchParams(data),
    headers: new Headers({
      'Content-type': 'application/x-www-form-urlencoded; charset=UTF-8'
    })