1 select * from S 2 select sname, 2014-Sage from S 3 select sname, sage from S where sage between 20 and 22 4 select * from S order by sdept asc, sage desc 5 select S.sno, sname from S, C, SC where S.sno=SC.sno and SC.cno=C.cno and Cname='数据库 '本回答被提问者和网友采纳