หลักสูตรฤดูหนาวใดบ้างที่เปิดสอนเท่านั้น ?ไม่จำเป็นต้องใช้ตารางทั้งหมด
Which Winter courses are only offered then ?It is not neccessary to use all the tables.
 instructor:  instructor_id [ int]  name [ varchar]  uniqname [ varchar] 
SELECT DISTINCT course.department, course.name, course.number FROM course INNER JOIN course_offering ON course.course_id = course_offering.course_id INNER JOIN semester ON semester.semester_id = course_offering.semester WHERE course.department = 'EECS' AND semester.semester = 'Winter' AND (SELECT COUNT(DISTINCT SEMESTERalias1.semester) FROM course AS COURSEalias1 INNER JOIN course_offering ON COURSEalias1.course_id = course_offering.course_id INNER JOIN semester AS SEMESTERalias1 ON SEMESTERalias1.semester_id = course_offering.semester WHERE course.course_id = COURSEalias1.course_id) = 1