Rails foreign key optional don't work

Question

I have troubles in my rails API with a model, my plays_cards model have some foreigns keys but with one I have troubles because I got Mysql2::Error: Field 'deck_id' doesn't have a default value but I don't need my deck and game to be obligatory.

PS: it works in development but not in production

This is my model:

class PlayCard < ApplicationRecord

# @!group RELATIONS
belongs_to :card
belongs_to :deck, optional: true
belongs_to :game, optional: true
belongs_to :user
# @!endgroup

# @!group VALIDATORS
validates :card_id, presence: true, blank: false, nill: false
validates :user_id, presence: true, blank: false, nill: false
validates :atk, presence: true, blank: false, nill: false, numericality: { greater_than_or_equal_to: 0 }
validates :hp, presence: true, blank: false, nill: false, numericality: { greater_than: 0 }
validates :uid, presence: true, allow_blank: false, allow_nil: false, length: { is: 4 }, uniqueness: true
# @!endgroup
end

And this is my migration:

class CreatePlayCards < ActiveRecord::Migration[5.2]
def change
create_table :play_cards do |t|
  t.references :card, foreign_key: true, null: false
  t.integer :atk, null: false
  t.integer :hp, null: false
  t.references :deck, foreign_key: true
  t.references :game, foreign_key: true
  t.string :uid, limit: 4, null: false

  t.timestamps
end
end
end

Do you have an idea ?

Have a nice day

SteveTurczyn · Accepted Answer · 2018-06-15T18:25:15.637

6

You don't need foreign_key: true on the t.refrences lines. They'll force referential integrity tests.

Roll back, then change the migration to...

t.references :deck
t.references :game

Alternatively you can just create the integer fields and bypass the database integrieites

t.integer :deck_id
t.integer :game_id

edited Jun 15 '18 at 18:25

answered Jun 15 '18 at 12:32

SteveTurczyn

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Edited my answer. Roll back the migration, try the second options in my answer, migrate, and let me know how you get on. – SteveTurczyn Jun 15 '18 at 18:26
1

you should use the references/belongs_to helper to make sure you get the expected column type. As of rails 5.1 or so primary keys are bigint, not int. – BM5k Jun 16 '18 at 02:56

score 1 · Answer 2 · edited Jun 15 '18 at 19:33

1

Try this:

 has_many :game, optional: true

edited Jun 15 '18 at 19:33

dwirony

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answered Jun 15 '18 at 13:39

Raj

66
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score 1 · Answer 3 · answered Jun 15 '18 at 18:56

There's nothing wrong with your actual Rails code as far as I can tell; I copied the relevant bits and ran it locally and it was fine. Although you do have some typos in the model you should fix (nill instead of nil). I think this is a database configuration problem, especially considering you said it works on development but not production. Googling the error message you posted Mysql2::Error: Field 'deck_id' doesn't have a default value gives results such as this. According to one of the answers there:

This is caused by the STRICT_TRANS_TABLES SQL mode defined in the %PROGRAMDATA%\MySQL\MySQL Server 5.6\my.ini file. Removing that setting and restarting MySQL should fix the problem.

score 0 · Answer 4 · answered Jun 17 '18 at 04:40

0

On rails 3, just change the property of your column like this

change_column :table, :column, :integer, null: true

answered Jun 17 '18 at 04:40

Amir El-Bashary

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Rails foreign key optional don't work

4 Answers4