ruby - Rails model relation MissingAttributeError -

i have models in application, , i'm trying save data got error:

activemodel::missingattributeerror (can't write unknown attribute product_id): app/controllers/admin_controller.rb:27:in `create_product'

i have 3 models

category model

class category < activerecord::base     has_many :features     has_many :products end 

migration:

class createcategories < activerecord::migration    def change      create_table :categories |t|      t.string :name, null: false      t.boolean :active, null: false, default: false       t.timestamps null: false    end end 

feature model

class feature < activerecord::base     has_and_belongs_to_many :categories     has_and_belongs_to_many :products  end 

migration

class createfeatures < activerecord::migration    def change       create_table :features |t|       t.belongs_to :category, index:true       t.string :name, null: false       t.timestamps null: false    end  end 

product model

class product < activerecord::base     belongs_to :category     has_many :features  end 

migration

class createproducts < activerecord::migration    def change       create_table :products |t|       t.belongs_to :category, index:true       t.string :name, null: false       t.text :rating, null: false       t.timestamps null: false     end  end 

i got error when try save product

activemodel::missingattributeerror (can't write unknown attribute product_id): app/controllers/admin_controller.rb:27:in `create_product'

i cannot figure out what's happening

any ideas?

thanks

if @ error, says

activemodel::missingattributeerror (can't write unknown attribute product_id)

so don't have product_id field , looking @ associations , features table migration, you forgot add product_id field in features table.

fix:

to add product_id field in features table need create new migration , migrate db:

rails g migration addproductidtofeatures product_id:integer rake db:migrate