摘要:
use stu --1 select sno,cno,grade from sc where sno in ( select sno from student where sdept = 'CS' ) --2 select cno from course where cno in( select c 阅读全文
摘要:
use stu select cno,cname from course where not exists( select * from sc where sno = '201215121' and cno=course.cno ) select sname from student where s 阅读全文