Ternura0.0的博客[例 3.55] 查询与“李勇”在同一个系...也可以用自身连接 select * from student s1,Student s2 where s1.Sdept=s2.Sdept and s2.Sname='李勇' [例 3.56]查询选修了课程名为“数据库”的学生学号和姓名 select Sn
CodeAsWind的博客GROUP BY SC.S#,Studengt.Sname HAVING COUNT(C#)=1; 24>查询男生、女生人数 SELECT COUNT(Ssex) AS 男生数 FROM Student GROUP BY Ssex HAVING Ssex='男'; SELECT COUNT(Ssex) AS 女生...