loading)
12）查询正在借阅的图书信息。
select * from book
where bnum in ( select bnum
from br
where brdate not like 'null' and brback like null )
13）查询借阅了机械工业出版社出版的书名中含有数'据库书'三个字的图书、或者借阅了科学出版社出版的书名中含有数'据库书'三个字的图书的读者姓名、书名。
select rname,bname from book,rea,br
where bname like '%数据库%' and rea.rnum in ( select br.rnum
from br,book
where bpub = '机械工业出版社' or bpub = '科学出版社' )
14）查询借阅了机械工业出版社出版的书名中含有数'据库书'三个字的图书并且也借阅了科学出版社出版的书名中含有数'据库书'三个字的图书的读者姓名、书名。
select rname,bname from book,rea,br
where bname = '%数据库%' and rea.rnum in ( select br.rnum
from br r1,br r2,book
where r1.rnum = r2.rnum and book.bnum =br.bnum and bpub = '机械工业出版社' and bpub = '科学出版社' )
15）查询借阅了机械工业出版社出版的书名中含有数'据库书'三个字的图书
但没有借阅了科学出版社出版的书名中含有数'据库书'三个字的图书的读者姓名、书名。
select rname,bname from book,rea,br
where bname like '%数据库%' and rea.rnum in ( select br.rnum
from br ,book
where br.bnum = book.bnum
and bpub = '机械工业出版社' and book.bnum in (select br.rnum
from br,book
where book.bnum = br.bnum and bname like '%数据库%' and bpub = '科学出版社')
)