Given that the \"Rails Way\" seems to be not to use foreign key constraints, I\'m looking for an alternative that will allow me to validate that the row a foreign key references
There is a plugin that helps you with this for belongs_to associations: Validates existence of. But, maybe you can add your own validation? What about something like this:
# Assuming your foreign key is user_id (which references the table User)
validate :user_id_exists
def user_id_exists
return false if User.find_by_id(self.user_id).nil?
end