以我学习SQL的经验,这样应该就可以了select S.S#, SN from S, C, SC Where S.S#=SC.S# and C.C#=SC.C# and C.CN='税收基础';
select s.s#,s.sn from s
join sc on s.s#=sc.s#
join c on sc.c#=c.c#
where c.cn='税收基础'
select S.S#, SNfrom S, C, SCwhere S.S#=SC.S# and C.C#=SC.C# and C.CN='税收基础'