Women in Technology

I have been trying to rewrite the tutorial so that it might be helpful for those who have Rails
2.0. I have since come to the conclusion that one need not manually import the data model into MySQL, because Rails 2.0 can do that now, such that:

in rails     becomes   in SQL

foo:string               foo varchar(255)

bar:text                 bar text

baz:integer              baz int

1. how does one express the following SQL statement as a rails statement:
   

   
   constraint fk_recipes_categories foreign key (category_id) references
   categories(id);
   

   
   


2. In part two of the tutorial:
   

   
   http://www.onlamp.com/pub/a/onlamp/2007/01/05/revisiting-ruby-on-rail...
   

   
   I thought that perhaps one could connect Recipe to Category by adding the
   following to the appropriate Rails 2.0 data model creation statements:
   

   
   has_many :recipes
   
   belongs_to :category
   
   

   
   When that didn't work, I added the two statements to the category & recipe
   model files, as instructed by the tutorial, to no avail. Are these two
   statements even pertinent when using Rails 2.0 to create our data model such
   that one can easily create Categories and assign Recipes to Categories ?