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Sequelize Relationships: hasOne vs belongsTo

Docs

• Docs Source
• belongsTo API
• hasOne API

Intro

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  useEffect(() => {
    async function omdbAPIRequest() {
      const requests = inventory.map((inventoryItem) => {
        return axios.get(
          `http://www.omdbapi.com/?i=${inventoryItem.id}&apikey=7f539340`
        );
      });

      const responses = await Promise.allSettled(requests);
      const responseDatas = responses.map((response) => response.value.data);

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Note: $> means command line input

Dependencies

Dependencies to use Sequelize $> npm install --save sequelize pg pg-hstore

Setup

Must create the DB first $> createdb my-music

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// primitives are 'passed by value' in JS
// meaning the value of the variable is copied over into a new local variable in the function

let n = 1;

function addOne(x) {
  x += 1;
  return x;
}

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Sure, here's a programming assignment for teaching the basics of regular expressions in Javascript:

Programming Assignment: Regular Expressions in Javascript

In this assignment, you will be using regular expressions to validate and manipulate strings in Javascript.

Task 1: Validate Email Addresses

Create a function validateEmail(email) that takes an email address as input and returns true if the email address is valid and false otherwise. An email address is considered valid if it meets the following criteria:

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/**
 * The main thing to see here is the 'optimal substructure' i.e.
 * perms([1, 2, 3]) could benefit from first knowing the result of
 * perms([1, 2]), which in turn could use perms([1]) as a starting point
 * and our basest of cases would be perms([]) at which point we have a
 * trivial problem (so was perms([1]) but I like to accoutn for empty).
 *
 * This points us to a helper function we are going to need, spread.
 * spread will 'spread' a single value into all possible array positions
 * at the previous level. So our logic is something like:

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Markup as an idea

What is markup

markup is just the general idea that you can represent information as 'code' using a data structure.

so for example, JSON counts as a markup language:

{

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import Data.List (inits, tails)

main :: IO ()
main = do
    print $ perms [1..4]
    print $ perms' "abcd"
    print $ perms'' [Nothing, Just 1, Just 2, Just 3]

perms, perms', perms'' :: [a] -> [[a]]

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// Product Model definition, called 'product' and associated with table 'products'
var Product = this.sequelize.define('product', {
  title: Sequelize.STRING
});

// User Model definition, called 'user' and associated with table 'users'
var User = this.sequelize.define('user', {
  first_name: Sequelize.STRING,
  last_name: Sequelize.STRING
});

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Global Scope, Inner Scope and Closures

This tutorial aims to cover the topics of

• Global Scope
• Inner Scope (or sometimes called Function Scope)
• and Closures

in the JavaScript language.

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