/Add_Association_between_2_tables_rails

Add_Association_between_2_tables_rails

We have 1 table

  • Job (title, description, company

We want to have an association between these tables

 rails g model Job title:string description:text company:string

We want to create a new table Category (name:string)

 rails g model Category name:string

We want to add a column called "name" of type string to the "jobs" table

 rails g migration AddNameToJobs name:string

And we want to add a column called "category_id" of type string to the "jobs" table

 rails g migration AddCategoryIdToJobs category_id:integer

Add associations between tables

  • Models > category.rb
class Category < ActiveRecord::Base
  has_many :jobs
end
  • Models > job.rb
class Job < ActiveRecord::Base
  belongs_to :category
end

And in _form of index job

<div class="form-group">
  <%= f.collection_select :category_id, Category.all, :id, :name, {promt: "Choose a category"} %>
</div>

Add strong params at controller jobs

def announce_params
  params.require(:job).permit(:title, :category_id)
end