barangerbenjamin

# DEEFINE AN ARRAY
empty_array = []  # an empty array
beatles = ["john", "paul", "ben"] # an array of 3 elements

# GET ELEMENT BY ITS INDEX
beatles[0]  # => "john"
beatles[1]  # => "paul"
beatles[2]  # => "ben"

# MODIFY AN ELEMENT

barangerbenjamin

# write test
# code method that takes sentence as parameter
# sentence needs to be broken down into words
# then into first letters of each word
# needs to return a string which is the acronym

def acronym(sentence)
  string = ""
  sentence.split(" ").each do |word|
    string += word[0].upcase

barangerbenjamin

# ONE LINE SYNTAX
 { |i| i * 2}

# MULTI-LINE SYNTAX
do |i|
  i * 2
end

barangerbenjamin

# def acronymize(sentence)
#   string = ""
#   sentence.split(" ").each do |word|
#     string += word[0].upcase
#   end
#   return string
# end

# redo using map

barangerbenjamin

# def acronymize(sentence)
#   string = ""
#   sentence.split(" ").each do |word|
#     string += word[0].upcase
#   end
#   return string
# end

# redo using map

barangerbenjamin

class Car

  def initialize(color)
    @color = color
    @engine_started = false
  end

  # allow you to read instance variable
  def color
    return @color

barangerbenjamin

class Citizen

  def initialize(first_name, last_name, age)
    @first_name = first_name
    @last_name = last_name
    @age = age
  end

  def can_vote?

barangerbenjamin

# List all customers (name + email), ordered alphabetically (no extra information)
# Should yield 59 results
SELECT first_name, last_name, email
FROM customers
ORDER BY last_name asc;

# List tracks (Name + Composer) of the Classical playlist
# Should yield 75 results
SELECT tracks.name, tracks.composer
FROM playlist_tracks

barangerbenjamin

class CreateDoctors < ActiveRecord::Migration[5.1]
  def change
    create_table :doctors do |t|
      t.string :first_name
      t.string :last_name
      t.timestamps
    end
  end
end

barangerbenjamin

# Q1 - What's a relational database?
a set of tables linked to each other thanks to a system of primary / foreign keys
# Q2 - What are the different "table relationships" you know?
1:n, 1 to many
n:n, many to many
1:1, one to one

# Q3 - Consider this e-library service. An author, defined by
# his name have several books.
# A book, defined by its title and publishing year,