I'm going to blog this so I can remember it. How to get Rails/ActiveRecord to wrap an existing table in a database, i.e. one that you don't want created or manipulated via migrations:
ruby script/generate model my_table --skip-migration
where my_table is the name of the table you are wrapping. This assumes you are already connected to the database (easy: edit config/database.yml).
It may be possible to simply derive a new class from ActiveRecord but the above is probably ensuring that everything is done properly.
In my case the database is being stuffed from some complex python code that I don't have the time/inclination to port to ruby/rails and I would rather the creation of the tables was still done through python. ActiveRecord being the wonder that it is will pick up the schema of the table and create wrappers automatically so you still don't need to tediously reiterate the column names/functions as you would in lesser frameworks.
It should be entirely possible to create views in MySQL and wrap them for Rails in this fashion although I found that creating views on a 20,000 record table causes the mysqld to take 99% cpu time for ten minutes afterwards. I know what you're saying, 'check your indexes', well I have.
Peter's Moblog
