Update 2 tables simutaneously with CI3

That model extends a CI_Model.  I was thinking, possibly incorrectly, that name is the database name which is model.  However as I think about your comment it looks like CI is looking for a table called 'users a as, user_profiles' which of course does not exist so the 'model' likely is the referring model.  This

PHP Code:

print_r($this->db->get_compiled_update('users AS a, user_profiles AS b')); 


will generate the query in my original post.