CREATE TABLE Course_Authors_and_Tutors (personal_name VARCHAR, family_name VARCHAR, author_id VARCHAR)
CREATE TABLE Courses (author_id VARCHAR)

Find the personal name, family name, and author ID of the course author that teaches the most courses.
SELECT T1.personal_name, T1.family_name, T2.author_id FROM Course_Authors_and_Tutors AS T1 JOIN Courses AS T2 ON T1.author_id = T2.author_id GROUP BY T2.author_id ORDER BY COUNT(*) DESC LIMIT 1
SELECT "T1"."personal_name", "T1"."family_name", "T2"."author_id" FROM "Course_Authors_and_Tutors" AS "T1" JOIN "Courses" AS "T2" ON "T1"."author_id" = "T2"."author_id" GROUP BY "T2"."author_id" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1