มีอาจารย์หลายคนที่สอน ECON 631 ใน Spring-Summer 2003 หรือไม่ ไม่จำเป็นต้องใช้ตารางทั้งหมด
Are there multiple professors who teach ECON 631 in Spring-Summer 2003 ?It is not neccessary to use all the tables.
 student:  student_id [ int]  lastname [ varchar]  firstname [ varchar]  program_id [ int]  declare_major [ varchar]  total_credit [ int]  total_gpa [ float]  entered_as [ varchar]  admit_term [ int]  predicted_graduation_semester [ int]  degree [ varchar]  minor [ varchar]  internship [ varchar] 
SELECT COUNT(DISTINCT instructor.instructor_id) FROM course, course_offering, instructor, offering_instructor, semester WHERE course.course_id = course_offering.course_id AND course.department = 'ECON' AND course.number = 631 AND offering_instructor.instructor_id = instructor.instructor_id AND offering_instructor.offering_id = course_offering.offering_id AND semester.semester = 'Spring-Summer' AND semester.semester_id = course_offering.semester AND semester.year = 2003