Validation failed Class must exist

Question

I have been (hours) trouble with associations in Rails. I found a lot of similar problems, but I couldn\'t apply for my case:

City\'s class:

class Ci         


        

Answer 1

Try the following:

belongs_to :city, optional: true

According to the new docs:

4.1.2.11 :optional

If you set the :optional option to true, then the presence of the associated object won't be validated. By default, this option is set to false.

Answer 2

params.require(:user).permit(:name, :citys_id)

It's a mistake, isn't it? (citys_id vs city_id)