Find the login name of the course author that teaches the course with name "advanced database".
create table courses (author_id varchar, course_name varchar, PRIMARY KEY (author_id)); create table course_authors_and_tutors (login_name varchar, author_id varchar, PRIMARY KEY (login_name))
select t1.login_name from course_authors_and_tutors as t1 join courses as t2 on t1.author_id = t2.author_id where t2.course_name = "advanced database"