How do I setup a 'type' table association in Rails? -

i'm sure has been asked (and answered) in numerous locations, , it's don't know how ask properly. here's issue, i'm trying setup simple product producttype association. i'm new ror, , since there's many builtin helpers in rails i'm looking solution instead of building out hand.

this have models (i'm quite confused how/when use singular/plural descriptors in rails).

product.rb

class product< activerecord::base  attr_accessible :name  has_one :product_tpe end 

pruduct_type.rb

class producttype< activerecord::base attr_accessible :name  belongs_to :product end 

this wrong (i think don't understand belongs_to: method enough). in usual sql relationships product table linked many 1 relationship product_types table.

i'm getting error:

sqlite3::sqlexception: no such column: product_types.product_id: select  "product_types".* "product_types"  "product_types"."product_id" = 1 limit 1 

since don't want product_id in product_types table, error makes sense; it's not did deliberately.

not complaint, i've gone through ror guide setting microposts sample app @ least. there other excellent tutorials on working ror's associations?

your relationship inverted. record foreign key should have belongs_to. also, looks want use has_many relationship on opposite end. so:

class product < activerecord::base   attr_accessible :name   belongs_to :product_tpe end  class producttype< activerecord::base   attr_accessible :name    has_many :products end 

lastly in migration should add in product_type_id integer column (add index faster lookups).