Mysql2::Error: Unknown column - mysql

Question

I work on rails 3.2.18 and mysql 5.6.20. I created migration which create new table and It looks like this:
class CreateRequest < ActiveRecord::Migration
def change
create_table :requests, id: false do |t|
t.string :id, null: false
t.integer :lesson_id, null: false
t.integer :user_id, null: false
t.boolean :approved, null: false, default: false
end
add_index :requests, :id, unique: true
end
end
I decided that I will use uuid as primary key. New record in DB I create like following:
def create_request(lesson)
request = Request.new.tap do |req|
req.id = SecureRandom.uuid
req.lesson_id = lesson.id
req.user_id = #user.id
end
request.save
end
So we have Request model and It is related to two other tables Lesson (one-to-one) ans User (one-to-many). No I will show you all models.
class PublicizeRequest < ActiveRecord::Base
self.table_name = "requests"
self.primary_key = "id"
has_one :lesson
belongs_to :user
end
class Lesson < ActiveRecord::Base
(...)
belongs_to :publicize_request
end
class User < ActiveRecord::Base
(...)
has_many :publicize_requests
end
Now I can describe main problem. If I get request from DB and I want to get user data I can do this simple:
#request.user
But If I want get lesson in the same way I get following error:
Mysql2::Error: Unknown column 'lessons.request_id' in 'where clause': SELECT `lessons`.* FROM `lessons` WHERE `lessons`.`archived` = 0 AND `lessons`.`request_id` = 'd0da41df-a9be-4575-ada0-538abe1f54a3' LIMIT 1
I am newbie in rails and I don't know how to deal with this. Thanks for all answers.

Answer 1

Your migration and relationship definition are not matching. The rule is that whichever table you have foreign key in, you define belongs_to relationship on that table's model.
You have defined lesson_id column in requests table, which means that Request model should have belongs_to :lesson.
class PublicizeRequest < ActiveRecord::Base
...
belongs_to :lesson
...
end
The reason you are getting the error is because you have has_one :lesson in Request model which would imply that you have belongs_to :request in your Lesson model if you have defined it, but you do not have request_id column in your lessons table.