All of those, please?
select t1.personal_name, t1.middle_name, t1.family_name from course_authors_and_tutors as t1 join courses as t2 on t1.author_id = t2.author_id where t2.course_name = "operating system" or t2.course_name = "data structure"
What are their login names?
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 = "operating system" or t2.course_name = "data structure"
What are the full names of the course authors who teach the course with the name "advanced database" please?
select t1.personal_name, t1.middle_name, t1.family_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"