Question

求 解答 谢谢

假定Oracle数据库中学生表为Student（id,studentname）、书籍表为 Book(id,bookname)、学生借阅表为
StudentBook(id,studentid,bookid,borrowdate).请编写SQL语句查询：
1） 今年(2011年）从未借阅过的书籍名称清单
2） 累计借阅次数最多的前十本书，得到下列信息：书名，借阅次数

Answer 1

1）
select distinct bookname from Book where id not in
(select distinct bookid from StudentBook where borrowdate between '20110101000000' and '20111231235959')
2）
select top 10 a.bookname,count(b.bookid) as Qty from Book a, StudentBook b
where a.id=b.bookid
group by a.bookname
order by count(b.bookid) desc

Answer 2

select bookname from Book
where id not in (select bookid from StudentBook);

select bookid,count(id) from StudentBook s join Book b
on s.bookid=b.id grouping by bookid
order by count(id) having rownum < 11

Answer 3

1.They'll probably make more cartoons in the future.
2.The first cartoons told stories using pictures.
3.Peter drew the pictures of flowers on the book.
4.It was the first cartoon film with sound.

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Answer 4

这么简单的sql 你自己考虑考虑吧

Answer 5

时空裂缝考虑是否