第1个回答 2013-11-06
create database StudentsDB
go
use StudentsDB
go
if exists(select name from sysobjects where name='Student' and xtype='u')
drop table Student
go
create table Student
(
StuID int,
name varchar(10),
)
go
insert into Student(StuID,name) values(1,'aa')
insert into Student(StuID,name) values(2,'bb')
insert into Student(StuID,name) values(3,'cc')
insert into Student(StuID,name) values(4,'dd')
go
create table CJ
(
StuID int,
km varchar(10),
kmcj float
)
go
insert into CJ(StuID,km,kmcj) values(1,'yw',78.5)
insert into CJ(StuID,km,kmcj) values(1,'sx',86)
insert into CJ(StuID,km,kmcj) values(1,'yy',69.7)
insert into CJ(StuID,km,kmcj) values(2,'yw',91)
insert into CJ(StuID,km,kmcj) values(2,'sx',79)
insert into CJ(StuID,km,kmcj) values(2,'yy',66)
insert into CJ(StuID,km,kmcj) values(3,'yw',81)
insert into CJ(StuID,km,kmcj) values(3,'sx',90)
go
select s.StuID,s.name,AVG(c.kmcj) as avgs from Student s join CJ c
on s.StuID = c.StuID group by s.StuID,s.name having AVG(c.kmcj)>80 order by avgs