判断它们能否用连接查询实现?如果能,请用ANSI语法形式写出该连接查询语句。
(1)select stuno,stuname from student
where stuno in (select stuno from stucou)
(2)select couno, couname, willnum from course
where willnum>(select avg(willnum) from course)
(3)select departname as '系部名称' from department
where departno=
(select departno from course where couno='018')
(4)select kind,avg(willnum) from course
group by kind
having avg(willnum)>=all
(select avg(willnum) from course group by kind)
(5)select couno,couname,kind,willnum from course
where kind<>'信息技术' and willnum>any
(select willnum from course where kind='信息技术')
(6)select stuno,stuname from student
where exists (select * from stucou
where stuno=student.stuno and couno='018')
(1)select stuno,stuname from student
where stuno in (select stuno from stucou)
(2)select couno, couname, willnum from course
where willnum>(select avg(willnum) from course)
(3)select departname as '系部名称' from department
where departno=
(select departno from course where couno='018')
(4)select kind,avg(willnum) from course
group by kind
having avg(willnum)>=all
(select avg(willnum) from course group by kind)
(5)select couno,couname,kind,willnum from course
where kind<>'信息技术' and willnum>any
(select willnum from course where kind='信息技术')
(6)select stuno,stuname from student
where exists (select * from stucou
where stuno=student.stuno and couno='018')
http://topic.csdn.net/u/20091130/21/fb718680-98ff-4afb-98d8-cff2f8293ed5.html?24281