4.sql

ssd7数据库的联系一到练习三

SELECT memno,fname,lname
FROM member
WHERE memno IN (
    SELECT DISTINCT borrowermemno
    FROM book
    WHERE callnumber IN (
        SELECT callnumber
        FROM Author
        WHERE lname = 'Collins'
        )
    GROUP BY borrowermemno
    HAVING COUNT(DISTINCT callnumber) = 2
);