数据库Sql试题
------------------------------------------------------create table students(st_id varchar(20),st_name varchar(50),sex varchar(10))insert into students(st_id,st_name,sex)select 'st001','张杰', '男' union allselect 'st002', '公孙燕飞' ,'男' union allselect 'st003', '王楠', '女' union allselect 'st004', '王伟', '男' union allselect 'st005','李燕纹', '女' union allselect 'st006', '孙武' ,'男' select *from students create table teachers(t_id varchar(20),t_name varchar(50),t_lesson varchar(50))insert into teachers select 't001', '张老师' ,'数学' union allselect 't002', '李老师', '英语' delete from resultscreate table results(r_id varchar(20),r_fenshu int,r_stid varchar(50),r_tid varchar(50))insert into resultsselect 'r001','90', 'st001', 't002' union allselect 'r002', '68', 'st005', 't001' union allselect 'r003', '92', 'st003' ,'t001' union allselect 'r004', '82', 'st006', 't002' union allselect 'r005', '70', 'st002', 't002' union allselect 'r006', '86', 'st002', 't001' union allselect 'r007', '57', 'st003', 't002' union allselect 'r008', '76', 'st006', 't001' union allselect 'r009', '55', 'st001', 't001' union allselect 'r010', '77', 'st004', 't002' union allselect 'r011', '58', 'st005', 't002'----------------------1.select st_idfrom studentswhere st_name = '王伟'2.select st_id,st_name from students where st_name like '__燕%'3 select st_name,len(st_name) as 名字长度 from students where sex ='男'4 select min(r_fenshu) as 最低分数 from teachers t inner join results r on t.t_id =r.r_tid where t_lesson ='数学' --这个是不考虑成绩中有null值的5 select s.st_id as 学生编号,r_fenshu as分数,r_tid as 课目号 from students s inner join results r on s.st_id =r.r_stid where s.sex='女' --如果还要课目的名称的话请用下面的 select s.st_id as 学生编号,r.r_fenshu as 分数,r.r_tid as 课目号,t.t_lesson as 课目名称 from students s inner join results r on s.st_id =r.r_stid inner join teachers t on r.r_tid = t.t_id where s.sex='女'6 select avg(r.r_fenshu) from results r inner join teachers t on r.r_tid = t.t_id where t.t_lesson='英语'7.select * from students s inner join results r on s.st_id =r.r_stid inner join teachers t on r.r_tid = t.t_idwhere s.st_id in (select top 2 st_id from students order by st_id desc)order by s.st_id desc8 select sum(r.r_fenshu) as 总分 from results r inner join students s on r.r_stid =s.st_id where s.st_name = '王楠'9.select distinct s.st_id,s.st_name from students s inner join results r on s.st_id = r.r_stid where st_id not in (select r_stid from results where r_fenshu<60) and st_id not in (select r_stid from results where r_fenshu >=90)10 update results set r_fenshu = r_fenshu + 10 --如果分数不可能大于100请用这句 set r_fenshu = case when r_fenshu + 10 <=100 then r_fenshu + 10 else 100 end where r_stid in (select st_id from students where sex='女')1 进阶题select t.t_name,count(*)from students s,teachers t,results rwhere r.r_tid = t.t_idand s.st_id =r.r_stidand r.r_fenshu >= 60and t.t_id in (select t_id from teachers where t_lesson='数学' )--and t_lesson='数学'group by t.t_name2 select top 1 sum(r_fenshu) as 总分,t.t_lesson,t_id,t_name from results r,teachers t where r.r_tid = t.t_id group by t.t_lesson,t_id,t_name order by 总分 desc3. delete from results where r_stid in (select r_stid from results group by r_stid having count(r_tid) = 1)1 选做题 select d.name from sysobjects d where d.xtype='U'2.select top 5 * from students order by newid()
