Fake a composite primary key? Rails

Question

I have a table with id|patient_id|client_id|active. A record is unique by patient_id, client_id meaning there should only be one enrollment per patient per client. Normally I wo

Answer 1

Add a UNIQUE constraint to your table across the two columns. Here's a reference for MySQL http://dev.mysql.com/doc/refman/5.0/en/constraint-primary-key.html