ActiveRecord::RecordInvalid: Validation failed: Team must exist - postgresql

Question

I am getting error ActiveRecord::RecordInvalid: Validation failed: Team must exist when I run rake db:seed.
I am trying to set an association between Players and Teams. I have data I want to seed into my database, but I am unsure if the error is being caused with how I have set up my association or how I have structured my data.
Team being the parent and Player being the child.
Models
# player.rb
class Player < ApplicationRecord
belongs_to :team, class_name: "Player"
validates :team, presence: true, allow_nil: true
end
# team.rb
class Team < ApplicationRecord
has_many :players
end
Routes
# routes.rb
Rails.application.routes.draw do
get 'welcome/index'
resources :players
resources :teams do
resources :players
end
root 'welcome#index'
end
Migrations
# create_players.rb
class CreatePlayers < ActiveRecord::Migration[5.1]
def change
create_table :players do |t|
t.belongs_to :team, index: true
t.string :name
t.string :shoots
t.string :catches
t.string :position
t.string :pos
t.integer :number
t.integer :gp
t.integer :goals
t.integer :assists
t.integer :points
t.integer :pim
t.integer :plusMinus
t.decimal :gaa
t.integer :svs
t.integer :team_id
t.references :teams
t.timestamps
end
end
end
# create_teams.rb
class CreateTeams < ActiveRecord::Migration[5.1]
def change
create_table :teams do |t|
t.string :team_name
t.string :abr
t.string :sm_logo
t.string :lg_logo
t.integer :player_id
t.timestamps
end
end
end
Data example of data attempting to seed
# Player data
players = Player.create!({
"name": "Some Guy",
"shoots": "Right",
"position": "Forward",
"pos": "F",
"number": 8,
"gp": 15,
"goals": 12,
"assists": 6,
"points": 18,
"pim": 12,
"plusMinus": 7,
"team_id": 1
})
# Team data
teams = Team.create!({
"team_name": "A Team",
"abr": "ATM"
})
Gemfile
source 'https://rubygems.org'
gem 'rails', '~> 5.1.0'
gem 'pg', '~> 0.18'
gem 'puma', '~> 3.7'
gem 'sass-rails', '~> 5.0'
gem 'uglifier', '>= 1.3.0'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby
#Bootstrap 4 and Tether gems
gem 'bootstrap', '~> 4.0.0.alpha6'
gem 'rails-assets-tether', '>= 1.3.3', source: 'https://rails-assets.org'
gem 'turbolinks', '~> 5'
gem 'jbuilder', '~> 2.5'
gem 'rails-ujs', '~> 0.1.0'
gem 'jquery-rails'
# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'
# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development
group :development, :test do
# Call 'byebug' anywhere in the code to stop execution and get a debugger console
gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
end
group :development do
# Access an IRB console on exception pages or by using <%= console %> anywhere in the code.
gem 'web-console', '>= 3.3.0'
gem 'listen', '>= 3.0.5', '< 3.2'
# Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
gem 'spring'
gem 'spring-watcher-listen', '~> 2.0.0'
end
# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]

Answer 1

First you need to create the team:
team = Team.create!({ team_name: "A Team", abr: "ATM" })
Notice that I pass a hash to the create! method, not an array with a hash, like you had in your example.
Then you can create the player and add them to the team:
player = Player.create!({
"name": "Some Guy",
"shoots": "Right",
"position": "Forward",
"pos": "F",
"number": 8,
"gp": 15,
"goals": 12,
"assists": 6,
"points": 18,
"pim": 12,
"plusMinus": 7,
"team": team
})
Notice that I am able to pass the team object to the Player.create! method. This will associate the player with the team. Otherwise you can just use the id.
player = Player.create!({
...
team_id: team.id
})
OR
player = Player.create!({
...
team_id: 1
})
The ellipsis (3 dots) should be replaced by the actual attributes as shown above.
Update
Remove the following lines from the create_players.rb migration:
t.integer :teams_id
t.references :teams
Remove the following line from the create_teams.rb migration:
t.integer :player__id
Writing t.belongs_to :player produces the same results as writing t.integer :player_id. It's just Rails syntactic sugar. Writing t.belongs_to :player or t.references :player is just a little more clear than writing t.integer :player_id
I'm assuming that you want one player to belong to one team (a one-to-many relationship). If you think that a player could belong to multiple teams (not usually the case, but I don't know what you're developing) than you would need to do a Google search for a Rails many-to-many relationship.

Answer 2

#Greg Answer thank you for your help. I have now found a working solution.
To fix I reverted back to a previous commit and decided to follow the following article:
https://www.learneroo.com/modules/137/nodes/767
My finished working code looks as follows:
Models
# Team model
class Team < ApplicationRecord
has_many :players
end
# Player model
class Player < ApplicationRecord
belongs_to :team
end
Migrations
# create_teams.rb
class CreateTeams < ActiveRecord::Migration[5.1]
def change
create_table :teams do |t|
t.string :team_name
t.string :abr
t.timestamps
end
end
end
# create_players.rb
class CreatePlayers < ActiveRecord::Migration[5.1]
def change
create_table :players do |t|
t.string :name
t.string :shoots
t.string :catches
t.string :position
t.string :posAbr
t.string :abr
t.integer :number
t.integer :gp
t.integer :goals
t.integer :assists
t.integer :points
t.integer :pim
t.integer :plusMinus
t.decimal :gaa
t.integer :svs
t.timestamps
end
end
end
# add_team_id_to_players.rb
class AddTeamIdToPlayers < ActiveRecord::Migration[5.1]
def change
add_column :players, :team_id, :integer
end
end
Seed data examples
# Team data
teams = Team.create([{
"team_name": "A Team",
"abr": "ATM"
}])
# Player data
players = Player.create!([{
"name": "Some Guy",
"shoots": "Right",
"position": "Forward",
"pos": "F",
"number": 8,
"gp": 15,
"goals": 12,
"assists": 6,
"points": 18,
"pim": 12,
"plusMinus": 7,
"team_id": 1
}])

Answer 3

Your association in the class Player is wrong, see when you must use:
If the name of the other model cannot be derived from the association name, you can use the :class_name option to supply the model name. For example, if a book belongs to an author, but the actual name of the model containing authors is Patron, you'd set things up this way:
class Book < ApplicationRecord
belongs_to :author, class_name: "Patron"
end
See all options to use this association: Rails Guide