ชั้นเรียน CMBIOL 995 ฤดูใบไม้ร่วงปี 2005 มีอาจารย์กี่คนสอน ?ไม่จำเป็นต้องใช้ตารางทั้งหมด
The Fall 2005 CMBIOL 995 classes are taught by how many professors ?It is not neccessary to use all the tables.
 program:  program_id [ int]  name [ varchar]  college [ varchar]  introduction [ 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 = 'CMBIOL' AND course.number = 995 AND offering_instructor.instructor_id = instructor.instructor_id AND offering_instructor.offering_id = course_offering.offering_id AND semester.semester = 'Fall' AND semester.semester_id = course_offering.semester AND semester.year = 2005