ActiveRecord associations & Validations

20210204090708_create_teams.rb

class CreateTeams < ActiveRecord::Migration[6.0]
  def change
    create_table :teams do |t|
      t.string      :name
      t.timestamps
    end
  end
end

20210204092155_create_players.rb

class CreatePlayers < ActiveRecord::Migration[6.0]
  def change
    create_table :players do |t|
      t.string      :name
      t.references  :team, foreign_key: true
      t.timestamps
    end
  end
end

20210204095403_create_users.rb

class CreateUsers < ActiveRecord::Migration[6.0]
  def change
    create_table :users do |t|
      t.string      :email
      t.timestamps
    end
  end
end

20210204095715_create_likes.rb

class CreateLikes < ActiveRecord::Migration[6.0]
  def change
    create_table :likes do |t|
      t.references  :player, foreign_key: true
      t.references  :user, foreign_key: true
      t.timestamps
    end
  end
end

20210204101950_add_name_to_users.rb

class AddNameToUsers < ActiveRecord::Migration[6.0]
  def change
    add_column :users, :first, :string
    add_column :users, :last, :string
  end
end

like.rb

class Like < ActiveRecord::Base
  belongs_to :user
  belongs_to :player
end

player.rb

class Player < ActiveRecord::Base
  belongs_to :team
  has_many :likes
  has_many :users, through: :likes
end

team.rb

class Team < ActiveRecord::Base
  has_many :players
end

user.rb

class User < ActiveRecord::Base
  has_many :likes

  validates :first, :last, presence: true
  validates :first, length: { minimum: 3 }
  validates :email, uniqueness: true
  validates :email, format: { with: /\A.*@.*\.com\z/ }
end