ปีหน้ารู้มั้ยศาสตราจารย์บัฟฟอร์ด อังจะสอนหลักสูตรไหน ?ไม่จำเป็นต้องใช้ทุกตารางเลย
Next year , do you know which courses Prof. Bufford Ang will be teaching ?It is not neccessary to use all the tables.
 ta:  campus_job_id [ int]  student_id [ int]  location [ varchar] 
SELECT DISTINCT course.department, course.name, course.number FROM course, course_offering, instructor, offering_instructor, semester WHERE course.course_id = course_offering.course_id AND instructor.name LIKE '%Bufford Ang%' AND offering_instructor.instructor_id = instructor.instructor_id AND offering_instructor.offering_id = course_offering.offering_id AND semester.semester_id = course_offering.semester AND ((semester.semester = 'FA' AND semester.year = 2016) OR (semester.semester = 'WN' AND semester.year = 2017))