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Ruby Build a Simple Ruby on Rails Application Customizing Forms Creating Relationships

Problem with associations

Hi, I'm using rails 4.0.4 and I'm getting problem when I try associate two tables. I have a table call Rooms with an user_id field and another table call Users. I created the migration and the association, but when I put an user_id on rooms form, rails is not saving the user_id on table Rooms.

Could anyone help me??

Thank you

1 Answer

Brandon Barrette
Brandon Barrette
20,485 Points

Strong parameters. You should google this and see how Rails 4 handles this (it's different than the videos).

Here's a good explanation: http://blog.sensible.io/2013/08/17/strong-parameters-by-example.html

Basically, you have to "permit" the fields you want the controller to have access to. If you don't permit them, then the controller doesn't know they exist. This is why your db column is empty.

Alternatively, you can do something like (Note: this assumes you are using Devise):

@room = current_user.rooms.new(params[:rooms])

This will automatically connect the association. This of course assumes that in your models you have:

has_many :rooms

belongs_to :user

I followed the instructions above, but now I got the follow error:

undefined method `rooms' for nil:NilClass

The undefined method is saying that it cant find the current_user, not the rooms