MostlyFocusedMike

SELECT SUM(cats.net_worth)
FROM owners
INNER JOIN cats_owners
ON owners.id = cats_owners.owner_id
JOIN cats ON cats_owners.cat_id = cats.id
WHERE cats_owners.owner_id = 2;

# which will return the following
SUM(cats.net_worth)
-------------------

MostlyFocusedMike

TABLE: cats  
id          name        age         breed          net_worth
----------  ----------  ----------  -------------  ----------
1           Maru        3           Scottish Fold  1000000
2           Hana        1           Tabby          21800
3           Grumpy Cat  4           Persian        181600
4           Lil\' Bub   2           Tortoiseshell  2000000

===============================================================
                            ||

MostlyFocusedMike

SELECT *
FROM owners
INNER JOIN cats_owners
ON owners.id = cats_owners.owner_id;

# which would return: 
id          name        cat_id      owner_id
----------  ----------  ----------  ----------
2           Sophie      3           2
3           Penny       3           3

MostlyFocusedMike

SELECT * 
FROM owners                                   
INNER JOIN cats_owners                        
ON owners.id = cats_owners.owner_id           
INNER JOIN cats                               
ON cats_owners.cat_id = cats.id;

# returns
id          name        cat_id      owner_id    id          name        age         breed       net_worth
----------  ----------  ----------  ----------  ----------  ----------  ----------  ----------  ----------

MostlyFocusedMike

SELECT cats.name AS cat, owners.name AS owner |P   | SELECT *
FROM owners                                   |R   | FROM owners
INNER JOIN cats_owners                        |E   | INNER JOIN cats_owners
ON owners.id = cats_owners.owner_id           |V   | ON owners.id = cats_owners.owner_id;
INNER JOIN cats                               |I   |
ON cats_owners.cat_id = cats.id;              |O   |  # which returned: 
                                              |U   | 
# returns this:                               |S ->| id          name        cat_id      owner_id                           
                                              |    | ----------  ----------  ----------  ----------                              
cat         owner                             |L   | 2           Sophie      3           2                             

MostlyFocusedMike

class Show
  attr_accessor :stand_up, :club
  @@all = []

  def initialize(stand_up, club)
    @stand_up = stand_up
    @club = club
    @@all << self
  end

MostlyFocusedMike

class StandUp                               |class Club                         
                                            |
  attr_accessor :name                       |  attr_accessor :club_name               
                                            |                        
  @@all = []                                |  @@all = []                 
                                            |
  def initialize(name)                      |  def initialize(club_name)                                   
    @name = name                            |    @club_name = club_name                                              
    @@all << self                           |    @@all << self                               
  end                                       |  end                          

MostlyFocusedMike

class BelongsToClass
  # accessors and whatnot
  @@all = []
  def initialize(has_many_class_a_obj, has_many_class_b_obj)
    @has_many_class_a_obj = has_many_class_a_obj
    @has_many_class_b_obj = has_many_class_b_obj
  end
  def self.all
    @@all
  end

MostlyFocusedMike

// we'll use arrow functions for brevity
let asynchProm = new Promise((resolve, reject) => {
  let fakeCode = 200;
  window.setTimeout(() => {
    if (fakeCode === 200) {
      resolve({status: "OK"})
    } else {
      reject({status: "ERROR"})
    }
  }, 3000);

MostlyFocusedMike

function grabber(resource, fakeStatus) {
  return new Promise((resolve, reject) => {
    window.setTimeout(() => {
      if (fakeStatus === 200) {
        resolve(`load ${resource}`)
      } else {
        reject("Error")
      }
    }, 3000);
  });