CREATE TABLE Course_Authors_and_Tutors (login_name VARCHAR2, author_id VARCHAR2)
CREATE TABLE Courses (author_id VARCHAR2, course_name VARCHAR2)

Find the login name of the course author that teaches the course with name 'advanced database'.
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"
SELECT "T1"."login_name" FROM "Course_Authors_and_Tutors" "T1" JOIN "Courses" "T2" ON "T1"."author_id" = "T2"."author_id" AND "T2"."course_name" = "advanced database"