( SELECT MemNo
FROM MEMBER, BOOK
WHERE MemNo = BorrowerMemNo AND
CallNumber = 'QA76.9.D26C66'
)
EXCEPT
( SELECT MemNo
FROM MEMBER, BOOK
WHERE MemNo = BorrowerMemNo AND
CallNumber = 'QA76.9.D7E53'
);
列出借出CallNumber为'QA76.9.D26C66'的书,但没有借出CallNumber为'QA76.9.D7E53'的书的人的MemNo
PS:createDB.sql是用mySQL的语法写的,不是用他说的 PostgreSQL