John Lee เขียนเอกสาร ACL กี่ฉบับในปีที่แล้ว ไม่จำเป็นต้องใช้ตารางทั้งหมด
How many ACL papers did John Lee written in the last year ?It is not neccessary to use all the tables.
 field:  fieldid [ int] 
SELECT DISTINCT COUNT(DISTINCT paper.paperid) FROM author, paper, venue, writes WHERE author.authorname = 'John Lee' AND paper.year >= YEAR(CURDATE()) - 1 AND venue.venueid = paper.venueid AND venue.venuename = 'ACL' AND writes.authorid = author.authorid AND writes.paperid = paper.paperid