Question

I just want to make sure I’m on the right track but when creating the migration for a HABTM that is using the same name like:

class Dog < ActiveRecord::Base
  has_and_belongs_to_many :dog_categories
end

class DogCategory < ActiveRecord::Base
  has_and_belongs_to_many :dogs
end

i’m thinking this…….

rails g migration dogs_dog_categories dog_id:integer dog_category_id:integer

This looks strange to me but is this how the migration/table should look?

Answer 1

According to rails guide:

The precedence between model names is calculated using the < operator for String. This means that if the strings are of different lengths, and the strings are equal when compared up to the shortest length, then the longer string is considered of higher lexical precedence than the shorter one. For example, one would expect the tables “paper_boxes” and “papers” to generate a join table name of “papers_paper_boxes” because of the length of the name “paper_boxes”, but it in fact generates a join table name of “paper_boxes_papers” (because the underscore ‘_’ is lexicographically less than ‘s’ in common encodings).

So, I think it should be dog_categories_dogs