human
Schema:
Course_Authors_and_Tutors (author_id, author_tutor_ATB, login_name, password, personal_name, middle_name, family_name, gender_mf, address_line_1)
Students (student_id, date_of_registration, date_of_latest_logon, login_name, password, personal_name, middle_name, family_name)
Subjects (subject_id, subject_name)
Courses (course_id, author_id, subject_id, course_name, course_description)
Student_Course_Enrolment (registration_id, student_id, course_id, date_of_enrolment, date_of_completion)
Student_Tests_Taken (registration_id, date_test_taken, test_result)
Please answer with SQL.
assistant
Sure, I understand.
human
List the author ids listed more than once in the courses
assistant
SELECT author_id FROM Courses GROUP by author_id having COUNT( author_id ) > 1;
human
Find the addresses and author IDs of the course authors that teach at least two courses.
assistant
SELECT T1.address_line_1 , 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 HAVING COUNT ( * ) > = 2;
human
How about those who teaches at least one course?
assistant
SELECT T1.address_line_1 , 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 HAVING COUNT( * ) > = 1 ;