数据库sql查询语句练习VIP专享VIP免费

查询语句 1、查询“001”课程比“002”课程成绩高的所有学生的学号； select a.S# from (select s#,score from SC where C#='001') as a,(selects#,score from SC where C#='002') as b where a.score>b.score and a.s#=b.s# 2、查询平均成绩大于 60分的同学的学号和平均成绩； select S#,avg(score) from sc group by S# having avg(score) >60 3、查询所有同学的学号、姓名、选课数、总成绩； select Student.S#,Student.Sname,count(SC.C#),sum(score) from Student left join SC on Student.S#=SC.S# group by Student.S#,Sname 4、查询姓“李”的老师的个数； select count(distinct(Tname)) from Teacher where Tname like '李%' 5、查询没学过“张三”老师课的同学的学号、姓名； select Student.S#,Student.Sname from Student where S# not in (select distinct( SC.S#) from SC,Course,Teacher where SC.C#=Course.C# and Teacher.T#=Course.T# andTeacher.Tname='张三') 6、查询学过“001”并且也学过编号“002”课程的同学的学号、姓名； select Student.S#,Student.Sname from Student,SC where Student.S#=SC.S#and SC.C#='001'and exists( Select * from SC as SC_2 where SC_2.S#=SC.S# andSC_2.C#='002') 7、查询学过“张三”老师所教的所有课的同学的学号、姓名； select S#,Sname from Student where S# in (select S# from SC ,Course ,Teacher where SC.C#=Course.C#and Teacher.T#=Course.T# and Teacher.Tname='张 三 ' group by S# having count(SC.C#)=(select count(C#) from Course,Teacher whereTeacher.T#=Course.T# and Tname='张三')) 8、查询课程编号“002”的成绩比课程编号“001”课程低的所有同学的学号、姓名； Select S#,Sname from (select Student.S#,Student.Sname,score ,(select score from SC SC_2 where SC_2.S#=Student.S# and SC_2.C#='002') as score2 from Student,SC where Student.S#=SC.S# and C#='001') S_2 where score260) 10、查询没...