ActiveModel::MissingAttributeError: can't write unknown attribute `ad_id' with FactoryGirl
Solution 1:
When you say:
has_one :image
Rails expects you to define an ad_id
field at the images
table. Given the way your associations are organised, I assume you have an image_id
and a logo_id
a the ads
table so instead of:
class Ad < ActiveRecord::Base
belongs_to :page
has_one :image
has_one :logo
end
You probably mean:
class Ad < ActiveRecord::Base
belongs_to :page
belongs_to :image
belongs_to :logo
end
If that's not the case then you need to add ad_id
columns to both Image
and Logo
.
Solution 2:
If you are getting this error while running the specs, it may be the newly added field that are not migrated in the test environment. So migrate it in the test environment with the below command
rake db:migrate db:test:prepare
Solution 3:
I ran into this same error and it took a while to figure out a fix. Just in case this helps someone else in the future, here's my scenario and what worked for me. Class names have been changed as this is for work:
I had 2 namespaced models:
Pantry::Jar
has_many :snacks, class_name: Pantry::Snack
accepts_nested_attributes_for :snacks
Pantry::Snack
belongs_to :pantry_jar, class_name: Pantry::Jar
When I would create a new jar with new snacks, I would get:
ActiveModel::MissingAttributeError: can't write unknown attribute `jar_id'
The fix was to change the has_many
to be more explicit about the foreign key:
has_many :snacks, class_name: Pantry::Snack, foreign_key: :pantry_jar_id
Solution 4:
Check your test database.
In my case, sometimes I did not modify the columns in the test database after modifying the development database after an incorrect migration.
Solution 5:
If you're getting the error while testing and you're using different repositories accessing the same test database, check if the migrations are equal among projects.
If you reset the database each time you're running the tests, only migrations available in that repository will be run, hence triggering the error related to the missing foreign key
ActiveModel::MissingAttributeError: can't write unknown attribute ad_id'
You should have the migration file with something like:
class AddAdReferenceToImage < ActiveRecord::Migration[5.0]
def change
add_reference :images, :ad, foreign_key: true
end
end