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Sequelize Lifecycle

Here's a list of all the Sequelize hooks: https://github.com/sequelize/sequelize/blob/main/lib/hooks.js

There are a four lifecycle events that an instance can go through:

1. Validate
2. Create
3. Destroy
4. Update

And Sequelize has default methods that allows us to hook into these lifecycle events!

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Exit Ticket: Day 10 - Express Custom Error Handling, Eager Loading with Sequelize

In your own words, what is eager loading?

• The equivalent to doing an INNER JOIN in SQL.
• Reference:
  • Sequelize: Eager Loading

    As briefly mentioned in the associations guide, eager Loading is the act of querying data of several models at once (one 'main' model and one or more associated models). At the SQL level, this is a query with one or more joins).

    When this is done, the associated models will be added by Sequelize in appropriately named, automatically created field(s) in the returned objects.

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Exit Ticket: Day 6 - Express and Handling Asynchronous Code

In your own words, what is a server?

• A HTTP server listens for HTTP requests and sends HTTP responses.
• Reference:
  • MDN: What is a web server?

What is the purpose of the package.json file in a Node project?

• Store a list of dependencies for the project
• Give the project a name

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/*
 * Migration
 */
'use strict';
module.exports = {
  up: function(queryInterface, Sequelize) {
    return queryInterface.createTable('Users', {
      firstName: {
        type: Sequelize.STRING
      },

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// connect() is a function that injects Redux-related props into your component.
// You can inject data and callbacks that change that data by dispatching actions.
function connect(mapStateToProps, mapDispatchToProps) {
  // It lets us inject component as the last step so people can use it as a decorator.
  // Generally you don't need to worry about it.
  return function (WrappedComponent) {
    // It returns a component
    return class extends React.Component {
      render() {
        return (

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-- Remove the history from 
rm -rf .git

-- recreate the repos from the current content only
git init
git add .
git commit -m "Initial commit"

-- push to the github remote repos ensuring you overwrite history
git remote add origin [email protected]:<YOUR ACCOUNT>/<YOUR REPOS>.git

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class MyPromise {
  constructor(executor) {
    if (typeof executor !== 'function') {
      throw new Error('Executor must be a function');
    }

    // Internal state. `$state` is the state of the promise, and `$chained` is
    // an array of the functions we need to call once this promise is settled.
    this.$state = 'PENDING';
    this.$chained = [];

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class Component extends React.Component {
  static getDerivedStateFromProps (nextProps, prevState) {
    // -> nextState
    // | Called after instantiating and when it receives new props
  }

  render () {
    // -> jsx
  }
  

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Articulating Learning Objectives

Effective course design begins with the question, what do I want my students to be able to do or produce by the end of this module?^[1] In answering this question, you will articulate course aims and objectives that will guide your choice of topics to cover in each module.

How to Write Effective Learning Objectives

The most effective learning objectives include active verbs and measurable outcomes.

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System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?