ในฤดูใบไม้ผลิ-ฤดูร้อน ปี 2001 มีอาจารย์สอน LING 446 กี่คน ?ไม่จำเป็นต้องใช้ตารางทั้งหมด
In Spring-Summer 2001 how many professors teach LING 446 ?It is not neccessary to use all the tables.
 student_record:  student_id [ int]  course_id [ int]  semester [ int]  grade [ varchar]  how [ varchar]  transfer_source [ varchar]  earn_credit [ varchar]  repeat_term [ varchar]  test_id [ 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 = 'LING' AND course.number = 446 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 = 2001