一个连串事关到的四二十个Sql语句

 

/*
标题:一个项目涉及到的4几个Sql语句(整理版)
小编:爱新觉罗.毓华(十八年风雨,守得冰山雪水六月春开)
时间:2010-05-10
地方:哈拉雷航天职业余大学学
注明:以下伍10个语句都依据测试数据开始展览过测试,最好每回只单独运转3个说话。
标题及描述:
–1.学生表
Student(S#,Sname,Sage,Ssex) –S# 学生编号,Sname 学生姓名,Sage
出生年月,Ssex 学生性别
–2.课程表
Course(C#,Cname,T#) –C# –课程编号,Cname 课程名称,T# 教师编号
–3.教师表
Teacher(T#,Tname) –T# 教授编号,Tname 教授姓名
–4.成绩表
SC(S#,C#,score) –S# 学生编号,C# 课程编号,score 分数
*/
–创造测试数据
create table Student(S# varchar(10),Sname nvarchar(10),Sage
datetime,Ssex nvarchar(10))
insert into Student values(’01’ , N’赵雷’ , ‘1990-01-01′ , N’男’)
insert into Student values(’02’ , N’钱电’ , ‘1990-12-21′ , N’男’)
insert into Student values(’03’ , N’孙风’ , ‘1990-05-20′ , N’男’)
insert into Student values(’04’ , N’李云’ , ‘1990-08-06′ , N’男’)
insert into Student values(’05’ , N’周梅’ , ‘1991-12-01′ , N’女’)
insert into Student values(’06’ , N’吴兰’ , ‘1992-03-01′ , N’女’)
insert into Student values(’07’ , N’郑竹’ , ‘1989-07-01′ , N’女’)
insert into Student values(’08’ , N’王菊’ , ‘1990-01-20′ , N’女’)
create table Course(C# varchar(10),Cname nvarchar(10),T#
varchar(10))
insert into Course values(’01’ , N’语文’ , ’02’)
insert into Course values(’02’ , N’数学’ , ’01’)
insert into Course values(’03’ , N’英语’ , ’03’)
create table Teacher(T# varchar(10),Tname nvarchar(10))
insert into Teacher values(’01’ , N’张三’)
insert into Teacher values(’02’ , N’李四’)
insert into Teacher values(’03’ , N’王五’)
create table SC(S# varchar(10),C# varchar(10),score decimal(18,1))
insert into SC values(’01’ , ’01’ , 80)
insert into SC values(’01’ , ’02’ , 90)
insert into SC values(’01’ , ’03’ , 99)
insert into SC values(’02’ , ’01’ , 70)
insert into SC values(’02’ , ’02’ , 60)
insert into SC values(’02’ , ’03’ , 80)
insert into SC values(’03’ , ’01’ , 80)
insert into SC values(’03’ , ’02’ , 80)
insert into SC values(’03’ , ’03’ , 80)
insert into SC values(’04’ , ’01’ , 50)
insert into SC values(’04’ , ’02’ , 30)
insert into SC values(’04’ , ’03’ , 20)
insert into SC values(’05’ , ’01’ , 76)
insert into SC values(’05’ , ’02’ , 87)
insert into SC values(’06’ , ’01’ , 31)
insert into SC values(’06’ , ’03’ , 34)
insert into SC values(’07’ , ’02’ , 89)
insert into SC values(’07’ , ’03’ , 98)
go

 

–① 、查询”01″课程比”02″课程成绩高的上学的小孩子的音讯及学科分数
–1.① 、查询同时设有”01″课程和”02″课程的情景
select a.* , b.score [课程’01’的分数],c.score [课程’02’的分数] from
Student a , SC b , SC c
where a.S# = b.S# and a.S# = c.S# and b.C# = ’01’ and c.C# = ’02’
and b.score > c.score
–1.贰 、查询同时设有”01″课程和”02″课程的景色和存在”01″课程但大概不设有”02″课程的图景(不存在时展现为null)(以下存在一样内容时不再解释)
select a.* , b.score [课程”01″的分数],c.score [课程”02″的分数] from
Student a
left join SC b on a.S# = b.S# and b.C# = ’01’
left join SC c on a.S# = c.S# and c.C# = ’02’
where b.score > isnull(c.score,0)

–② 、查询”01″课程比”02″课程成绩低的学员的音信及教程分数
–2.① 、查询同时存在”01″课程和”02″课程的场地
select a.* , b.score [课程’01’的分数],c.score [课程’02’的分数] from
Student a , SC b , SC c
where a.S# = b.S# and a.S# = c.S# and b.C# = ’01’ and c.C# = ’02’
and b.score < c.score
–2.② 、查询同时存在”01″课程和”02″课程的景观和不设有”01″课程但存在”02″课程的景况
select a.* , b.score [课程”01″的分数],c.score [课程”02″的分数] from
Student a
left join SC b on a.S# = b.S# and b.C# = ’01’
left join SC c on a.S# = c.S# and c.C#航天科工, = ’02’
where isnull(b.score,0) < c.score

–③ 、查询平均战绩超乎等于陆十三分的校友的学员编号和学生姓名和平均成绩
select a.S# , a.Sname , cast(avg(b.score) as decimal(18,2))
avg_score
from Student a , sc b
where a.S# = b.S#
group by a.S# , a.Sname
having cast(avg(b.score) as decimal(18,2)) >= 60
order by a.S#

–4、查询平均战表小于伍二十一分的同学的上学的儿童编号和学员姓名和平均成绩
–4.① 、查询在sc表存在战绩的学员新闻的SQL语句。
select a.S# , a.Sname , cast(avg(b.score) as decimal(18,2))
avg_score
from Student a , sc b
where a.S# = b.S#
group by a.S# , a.Sname
having cast(avg(b.score) as decimal(18,2)) < 60
order by a.S#
–4.贰 、查询在sc表中不存在成绩的学员音讯的SQL语句。
select a.S# , a.Sname , isnull(cast(avg(b.score) as decimal(18,2)),0)
avg_score
from Student a left join sc b
on a.S# = b.S#
group by a.S# , a.Sname
having isnull(cast(avg(b.score) as decimal(18,2)),0) < 60
order by a.S#

–伍 、查询全体同学的学生编号、学生姓名、选课总数、全体课程的总成绩
–5.壹 、查询全数有成就的SQL。
select a.S# [学员编号], a.Sname [学生姓名], count(b.C#) 选课总数,
sum(score) [有着科指标总成绩]
from Student a , SC b
where a.S# = b.S#
group by a.S#,a.Sname
order by a.S#
–5.二 、查询全部(包涵有成就和无战表)的SQL。
select a.S# [学员编号], a.Sname [学生姓名], count(b.C#) 选课总数,
sum(score) [负有科目标总成绩]
from Student a left join SC b
on a.S# = b.S#
group by a.S#,a.Sname
order by a.S#

–⑥ 、查询”李”姓老师的多寡
–方法1
select count(Tname) [“李”姓老师的数量] from Teacher where Tname like
N’李%’
–方法2
select count(Tname) [“李”姓老师的数码] from Teacher where
left(Tname,1) = N’李’
/*

“李”姓老师的多少

1
*/

–柒 、查询学过”张三”老师讲解的同室的音讯
select distinct Student.* from Student , SC , Course , Teacher
where Student.S# = SC.S# and SC.C# = Course.C# and Course.T# =
Teacher.T# and Teacher.Tname = N’张三’
order by Student.S#

–八 、查询没学过”张三”老师上课的校友的音信
select m.* from Student m where S# not in (select distinct SC.S# from
SC , Course , Teacher where SC.C# = Course.C# and Course.T# =
Teacher.T# and Teacher.Tname = N’张三’) order by m.S#

–九 、查询学过数码为”01″并且也学过数码为”02″的课程的同学的音讯
–方法1
select Student.* from Student , SC where Student.S# = SC.S# and
SC.C# = ’01’ and exists (Select 1 from SC SC_2 where SC_2.S# =
SC.S# and SC_2.C# = ’02’) order by Student.S#
–方法2
select Student.* from Student , SC where Student.S# = SC.S# and
SC.C# = ’02’ and exists (Select 1 from SC SC_2 where SC_2.S# =
SC.S# and SC_2.C# = ’01’) order by Student.S#
–方法3
select m.* from Student m where S# in
(
select S# from
(
select distinct S# from SC where C# = ’01’
union all
select distinct S# from SC where C# = ’02’
) t group by S# having count(1) = 2
)
order by m.S#

–⑩ 、查询学过数码为”01″不过从未学过数码为”02″的课程的同桌的音信
–方法1
select Student.* from Student , SC where Student.S# = SC.S# and
SC.C# = ’01’ and not exists (Select 1 from SC SC_2 where SC_2.S# =
SC.S# and SC_2.C# = ’02’) order by Student.S#
–方法2
select Student.* from Student , SC where Student.S# = SC.S# and
SC.C# = ’01’ and Student.S# not in (Select SC_2.S# from SC SC_2
where SC_2.S# = SC.S# and SC_2.C# = ’02’) order by Student.S#

–1壹 、查询没有学全全体课程的同学的新闻
–11.1、
select Student.*
from Student , SC
where Student.S# = SC.S#
group by Student.S# , Student.Sname , Student.Sage , Student.Ssex
having count(C#) < (select count(C#) from Course)
–11.2
select Student.*
from Student left join SC
on Student.S# = SC.S#
group by Student.S# , Student.Sname , Student.Sage , Student.Ssex
having count(C#) < (select count(C#) from Course)

–1贰 、查询至少有一门课与学号为”01″的同桌所学相同的同桌的消息
select distinct Student.* from Student , SC where Student.S# = SC.S#
and SC.C# in (select C# from SC where S# = ’01’) and Student.S#
<> ’01’

–1叁 、查询和”01″号的同学学习的学科完全相同的别的同学的音信
select Student.* from Student where S# in
(select distinct SC.S# from SC where S# <> ’01’ and SC.C# in
(select distinct C# from SC where S# = ’01’)
group by SC.S# having count(1) = (select count(1) from SC where
S#=’01’))

–1肆 、查询没学过”张三”老师教学的任一门科目标学生姓名
select student.* from student where student.S# not in
(select distinct sc.S# from sc , course , teacher where sc.C# =
course.C# and course.T# = teacher.T# and teacher.tname = N’张三’)
order by student.S#

–1五 、查询两门及其以上不及格课程的同窗的学号,姓名及其平均战表
select student.S# , student.sname , cast(avg(score) as decimal(18,2))
avg_score from student , sc
where student.S# = SC.S# and student.S# in (select S# from SC where
score < 60 group by S# having count(1) >= 2)
group by student.S# , student.sname

–1陆 、检索”01″课程分数小于60,按分数降序排列的学生新闻
select student.* , sc.C# , sc.score from student , sc
where student.S# = SC.S# and sc.score < 60 and sc.C# = ’01’
order by sc.score desc

–1柒 、按平均成绩从高到低彰显所有学员的具有科指标成就以及平均成绩
–17.1 SQL 2000 静态
select a.S# 学生编号 , a.Sname 学生姓名 ,
max(case c.Cname when N’语文’ then b.score else null end) [语文],
max(case c.Cname when N’数学’ then b.score else null end) [数学],
max(case c.Cname when N’英语’ then b.score else null end) [英语],
cast(avg(b.score) as decimal(18,2)) 平均分
from Student a
left join SC b on a.S# = b.S#
left join Course c on b.C# = c.C#
group by a.S# , a.Sname
order by 平均分 desc
–17.2 SQL 2000 动态
declare @sql nvarchar(4000)
set @sql = ‘select a.S# ‘ + N’学生编号’ + ‘ , a.Sname ‘ + N’学生姓名’
select @sql = @sql + ‘,max(case c.Cname when N”’+Cname+”’ then b.score
else null end) [‘+Cname+’]’
from (select distinct Cname from Course) as t
set @sql = @sql + ‘ , cast(avg(b.score) as decimal(18,2)) ‘ + N’平均分’

  • ‘ from Student a left join SC b on a.S# = b.S# left join Course c on
    b.C# = c.C#
    group by a.S# , a.Sname order by ‘ + N’平均分’ + ‘ desc’
    exec(@sql)

–17.3 有关sql 2006的动静态写法参见作者的篇章《普通行列转换(version
2.0)》或《普通行列转换(version 3.0)》。

 

 

–18、查询各科成绩最高分、最低分和平均分:以如下方式显示:课程ID,课程name,最高分,最低分,平均分,及格率,中等率,卓越率,非凡率
–及格为>=60,中等为:70-80,优良为:80-90,优秀为:>=90
–方法1
select m.C# [学科编号], m.Cname [课程名称],
max(n.score) [最高分],
min(n.score) [最低分],
cast(avg(n.score) as decimal(18,2)) [平均分],
cast((select count(1) from SC where C# = m.C# and score >=
60)*100.0 / (select count(1) from SC where C# = m.C#) as
decimal(18,2)) [及格率(%)],
cast((select count(1) from SC where C# = m.C# and score >= 70 and
score < 80 )*100.0 / (select count(1) from SC where C# = m.C#) as
decimal(18,2)) [中等率(%)],
cast((select count(1) from SC where C# = m.C# and score >= 80 and
score < 90 )*100.0 / (select count(1) from SC where C# = m.C#) as
decimal(18,2)) [优良率(%)],
cast((select count(1) from SC where C# = m.C# and score >=
90)*100.0 / (select count(1) from SC where C# = m.C#) as
decimal(18,2)) [优秀率(%)]
from Course m , SC n
where m.C# = n.C#
group by m.C# , m.Cname
order by m.C#
–方法2
select m.C# [学科编号], m.Cname [课程名称],
(select max(score) from SC where C# = m.C#) [最高分],
(select min(score) from SC where C# = m.C#) [最低分],
(select cast(avg(score) as decimal(18,2)) from SC where C# = m.C#)
[平均分],
cast((select count(1) from SC where C# = m.C# and score >=
60)*100.0 / (select count(1) from SC where C# = m.C#) as
decimal(18,2)) [及格率(%)],
cast((select count(1) from SC where C# = m.C# and score >= 70 and
score < 80 )*100.0 / (select count(1) from SC where C# = m.C#) as
decimal(18,2)) [中等率(%)],
cast((select count(1) from SC where C# = m.C# and score >= 80 and
score < 90 )*100.0 / (select count(1) from SC where C# = m.C#) as
decimal(18,2)) [优良率(%)],
cast((select count(1) from SC where C# = m.C# and score >=
90)*100.0 / (select count(1) from SC where C# = m.C#) as
decimal(18,2)) [优秀率(%)]
from Course m
order by m.C#

–1⑨ 、按各科战表实行排序,并展示排名
–19.1 sql 两千用子查询完成
–Score重复时保留排行空缺
select t.* , px = (select count(1) from SC where C# = t.C# and score
> t.score) + 1 from sc t order by t.c# , px
–Score重复时合并名次
select t.* , px = (select count(distinct score) from SC where C# =
t.C# and score >= t.score) from sc t order by t.c# , px
–19.2 sql 2005用rank,DENSE_RANK完成
–Score重复时保留排名空缺(rank完结)
select t.* , px = rank() over(partition by c# order by score desc)
from sc t order by t.C# , px
–Score重复时合并排名(DENSE_RANK完成)
select t.* , px = DENSE_RANK() over(partition by c# order by score
desc) from sc t order by t.C# , px

–20、查询学生的总战绩并进行排行
–20.1 查询学生的总战绩
select m.S# [学员编号] ,
m.Sname [学员姓名] ,
isnull(sum(score),0) [总成绩]
from Student m left join SC n on m.S# = n.S#
group by m.S# , m.Sname
order by [总成绩] desc
–20.2 查询学生的总战绩并进行排名,sql
三千用子查询完结,分总分重复时保留排行空缺和不保留排行空缺三种。
select t1.* , px = (select count(1) from
(
select m.S# [学生编号] ,
m.Sname [学员姓名] ,
isnull(sum(score),0) [总成绩]
from Student m left join SC n on m.S# = n.S#
group by m.S# , m.Sname
) t2 where 总成绩 > t1.总成绩) + 1 from
(
select m.S# [学生编号] ,
m.Sname [学生姓名] ,
isnull(sum(score),0) [总成绩]
from Student m left join SC n on m.S# = n.S#
group by m.S# , m.Sname
) t1
order by px

select t1.* , px = (select count(distinct 总成绩) from
(
select m.S# [学员编号] ,
m.Sname [学生姓名] ,
isnull(sum(score),0) [总成绩]
from Student m left join SC n on m.S# = n.S#
group by m.S# , m.Sname
) t2 where 总成绩 >= t1.总成绩) from
(
select m.S# [学生编号] ,
m.Sname [学员姓名] ,
isnull(sum(score),0) [总成绩]
from Student m left join SC n on m.S# = n.S#
group by m.S# , m.Sname
) t1
order by px
–20.3 查询学生的总战表并实行排名,sql
二〇〇五用rank,DENSE_RANK达成,分总分重复时保留排名空缺和不保留排名空缺三种。
select t.* , px = rank() over(order by [总成绩] desc) from
(
select m.S# [学员编号] ,
m.Sname [学员姓名] ,
isnull(sum(score),0) [总成绩]
from Student m left join SC n on m.S# = n.S#
group by m.S# , m.Sname
) t
order by px

select t.* , px = DENSE_RANK() over(order by [总成绩] desc) from
(
select m.S# [学生编号] ,
m.Sname [学员姓名] ,
isnull(sum(score),0) [总成绩]
from Student m left join SC n on m.S# = n.S#
group by m.S# , m.Sname
) t
order by px

–2一 、查询分裂老师所教差别学科平均分从高到低显示
select m.T# , m.Tname , cast(avg(o.score) as decimal(18,2))
avg_score
from Teacher m , Course n , SC o
where m.T# = n.T# and n.C# = o.C#
group by m.T# , m.Tname
order by avg_score desc

–2② 、查询全部课程的成就第一名到第1名的学生音信及该学科战绩
–22.1 sql 3000用子查询完毕
–Score重复时保留排名空缺
select * from (select t.* , px = (select count(1) from SC where C# =
t.C# and score > t.score) + 1 from sc t) m where px between 2 and 3
order by m.c# , m.px
–Score重复时合并排行
select * from (select t.* , px = (select count(distinct score) from SC
where C# = t.C# and score >= t.score) from sc t) m where px between
2 and 3 order by m.c# , m.px
–22.2 sql 2005用rank,DENSE_RANK完成
–Score重复时保留排名空缺(rank完结)
select * from (select t.* , px = rank() over(partition by c# order by
score desc) from sc t) m where px between 2 and 3 order by m.C# ,
m.px
–Score重复时合并排名(DENSE_RANK完成)
select * from (select t.* , px = DENSE_RANK() over(partition by c#
order by score desc) from sc t) m where px between 2 and 3 order by
m.C# , m.px

–2③ 、总结各科战表各分数段人数:课程编号,课程名称,[100-85],[85-70],[70-60],[0-60]及所占比例
–23.1
计算各科成绩各分数段人数:课程编号,课程名称,[100-85],[85-70],[70-60],[0-60]
–横向突显
select Course.C# [学科编号] , Cname as [课程名称] ,
sum(case when score >= 85 then 1 else 0 end) [85-100],
sum(case when score >= 70 and score < 85 then 1 else 0 end)
[70-85],
sum(case when score >= 60 and score < 70 then 1 else 0 end)
[60-70],
sum(case when score < 60 then 1 else 0 end) [0-60]
from sc , Course
where SC.C# = Course.C#
group by Course.C# , Course.Cname
order by Course.C#
–纵向显示1(展现存在的分数段)
select m.C# [课程编号] , m.Cname [课程名称] , 分数段 = (
case when n.score >= 85 then ’85-100′
when n.score >= 70 and n.score < 85 then ’70-85′
when n.score >= 60 and n.score < 70 then ’60-70′
else ‘0-60’
end) ,
count(1) 数量
from Course m , sc n
where m.C# = n.C#
group by m.C# , m.Cname , (
case when n.score >= 85 then ’85-100′
when n.score >= 70 and n.score < 85 then ’70-85′
when n.score >= 60 and n.score < 70 then ’60-70′
else ‘0-60’
end)
order by m.C# , m.Cname , 分数段
–纵向突显2(突显存在的分数段,不设有的分数段用0显示)
select m.C# [课程编号] , m.Cname [课程名称] , 分数段 = (
case when n.score >= 85 then ’85-100′
when n.score >= 70 and n.score < 85 then ’70-85′
when n.score >= 60 and n.score < 70 then ’60-70′
else ‘0-60’
end) ,
count(1) 数量
from Course m , sc n
where m.C# = n.C#
group by all m.C# , m.Cname , (
case when n.score >= 85 then ’85-100′
when n.score >= 70 and n.score < 85 then ’70-85′
when n.score >= 60 and n.score < 70 then ’60-70′
else ‘0-60’
end)
order by m.C# , m.Cname , 分数段

–23.2
总括各科成绩各分数段人数:课程编号,课程名称,[100-85],[85-70],[70-60],[<60]及所占比例
–横向彰显
select m.C# 课程编号, m.Cname 课程名称,
(select count(1) from SC where C# = m.C# and score < 60)
[0-60],
cast((select count(1) from SC where C# = m.C# and score <
60)*100.0 / (select count(1) from SC where C# = m.C#) as
decimal(18,2)) [百分比(%)],
(select count(1) from SC where C# = m.C# and score >= 60 and score
< 70) [60-70],
cast((select count(1) from SC where C# = m.C# and score >= 60 and
score < 70)*100.0 / (select count(1) from SC where C# = m.C#) as
decimal(18,2)) [百分比(%)],
(select count(1) from SC where C# = m.C# and score >= 70 and score
< 85) [70-85],
cast((select count(1) from SC where C# = m.C# and score >= 70 and
score < 85)*100.0 / (select count(1) from SC where C# = m.C#) as
decimal(18,2)) [百分比(%)],
(select count(1) from SC where C# = m.C# and score >= 85)
[85-100],
cast((select count(1) from SC where C# = m.C# and score >=
85)*100.0 / (select count(1) from SC where C# = m.C#) as
decimal(18,2)) [百分比(%)]
from Course m
order by m.C#
–纵向显示1(彰显存在的分数段)
select m.C# [课程编号] , m.Cname [课程名称] , 分数段 = (
case when n.score >= 85 then ’85-100′
when n.score >= 70 and n.score < 85 then ’70-85′
when n.score >= 60 and n.score < 70 then ’60-70′
else ‘0-60’
end) ,
count(1) 数量 ,
cast(count(1) * 100.0 / (select count(1) from sc where C# = m.C#) as
decimal(18,2)) [百分比(%)]
from Course m , sc n
where m.C# = n.C#
group by m.C# , m.Cname , (
case when n.score >= 85 then ’85-100′
when n.score >= 70 and n.score < 85 then ’70-85′
when n.score >= 60 and n.score < 70 then ’60-70′
else ‘0-60’
end)
order by m.C# , m.Cname , 分数段
–纵向呈现2(呈现存在的分数段,不设有的分数段用0展现)
select m.C# [课程编号] , m.Cname [课程名称] , 分数段 = (
case when n.score >= 85 then ’85-100′
when n.score >= 70 and n.score < 85 then ’70-85′
when n.score >= 60 and n.score < 70 then ’60-70′
else ‘0-60’
end) ,
count(1) 数量 ,
cast(count(1) * 100.0 / (select count(1) from sc where C# = m.C#) as
decimal(18,2)) [百分比(%)]
from Course m , sc n
where m.C# = n.C#
group by all m.C# , m.Cname , (
case when n.score >= 85 then ’85-100′
when n.score >= 70 and n.score < 85 then ’70-85′
when n.score >= 60 and n.score < 70 then ’60-70′
else ‘0-60’
end)
order by m.C# , m.Cname , 分数段

 

 

 

–2四 、查询学毕生均战绩及其名次
–24.1 查询学生的平分战绩并举行名次,sql
2000用子查询达成,分平均战绩再度时保留名次空缺和不保留排行空缺三种。
select t1.* , px = (select count(1) from
(
select m.S# [学生编号] ,
m.Sname [学员姓名] ,
isnull(cast(avg(score) as decimal(18,2)),0) [平均成绩]
from Student m left join SC n on m.S# = n.S#
group by m.S# , m.Sname
) t2 where 平均战绩 > t1.等分成绩) + 1 from
(
select m.S# [学员编号] ,
m.Sname [学员姓名] ,
isnull(cast(avg(score) as decimal(18,2)),0) [平均成绩]
from Student m left join SC n on m.S# = n.S#
group by m.S# , m.Sname
) t1
order by px

select t1.* , px = (select count(distinct 平均成绩) from
(
select m.S# [学生编号] ,
m.Sname [学员姓名] ,
isnull(cast(avg(score) as decimal(18,2)),0) [平均成绩]
from Student m left join SC n on m.S# = n.S#
group by m.S# , m.Sname
) t2 where 平均战表 >= t1.平分战表) from
(
select m.S# [学员编号] ,
m.Sname [学生姓名] ,
isnull(cast(avg(score) as decimal(18,2)),0) [平均战表]
from Student m left join SC n on m.S# = n.S#
group by m.S# , m.Sname
) t1
order by px
–24.2 查询学生的平分成绩并拓展排行,sql
二〇〇六用rank,DENSE_RANK达成,分平均战表再一次时保留排行空缺和不保留排行空缺三种。
select t.* , px = rank() over(order by [平均战表] desc) from
(
select m.S# [学生编号] ,
m.Sname [学生姓名] ,
isnull(cast(avg(score) as decimal(18,2)),0) [平均成绩]
from Student m left join SC n on m.S# = n.S#
group by m.S# , m.Sname
) t
order by px

select t.* , px = DENSE_RANK() over(order by [平均成绩] desc) from
(
select m.S# [学生编号] ,
m.Sname [学员姓名] ,
isnull(cast(avg(score) as decimal(18,2)),0) [平均成绩]
from Student m left join SC n on m.S# = n.S#
group by m.S# , m.Sname
) t
order by px

–2伍 、查询各科成绩前三名的笔录
–25.1 分数重复时保留排名空缺
select m.* , n.C# , n.score from Student m, SC n where m.S# = n.S#
and n.score in
(select top 3 score from sc where C# = n.C# order by score desc) order
by n.C# , n.score desc
–25.2 分数重复时不保留排行空缺,合并排名
–sql 三千用子查询达成
select * from (select t.* , px = (select count(distinct score) from SC
where C# = t.C# and score >= t.score) from sc t) m where px between
1 and 3 order by m.c# , m.px
–sql 2005用DENSE_RANK实现
select * from (select t.* , px = DENSE_RANK() over(partition by c#
order by score desc) from sc t) m where px between 1 and 3 order by
m.C# , m.px

–2⑥ 、查询每门课程被选修的上学的小孩子数
select c# , count(S#)[学生数] from sc group by C#

–2⑦ 、查询出唯有两门课程的万事上学的小孩子的学号和姓名
select Student.S# , Student.Sname
from Student , SC
where Student.S# = SC.S#
group by Student.S# , Student.Sname
having count(SC.C#) = 2
order by Student.S#

–2⑧ 、查询男子、女子人数
select count(Ssex) as 匹老婆数 from Student where Ssex = N’男’
select count(Ssex) as 女子人数 from Student where Ssex = N’女’
select sum(case when Ssex = N’男’ then 1 else 0 end)
[男生人数],sum(case when Ssex = N’女’ then 1 else 0 end) [女孩子人数]
from student
select case when Ssex = N’男’ then N’匹内人数’ else N’女孩子人数’ end
[子女情事] , count(1) [人数] from student group by case when Ssex =
N’男’ then N’男子人数’ else N’女子人数’ end

–2九 、查询名字中隐含”风”字的学员新闻
select * from student where sname like N’%风%’
select * from student where charindex(N’风’ , sname) > 0

–30、查询同名同性学生名单,并总结同有名气的人数
select Sname [学员姓名], count(*) [人数] from Student group by
Sname having count(*) > 1

–3一 、查询一九九零年诞生的学生名单(注:Student表中Sage列的档次是datetime)
select * from Student where year(sage) = 1990
select * from Student where datediff(yy,sage,’1990-01-01′) = 0
select * from Student where datepart(yy,sage) = 1990
select * from Student where convert(varchar(4),sage,120) = ‘1990’

–3② 、查询每门学科的平分战绩,结果按平均成绩降序排列,平均成绩一样时,按学科编号升序排列
select m.C# , m.Cname , cast(avg(n.score) as decimal(18,2))
avg_score
from Course m, SC n
where m.C# = n.C#
group by m.C# , m.Cname
order by avg_score desc, m.C# asc

–3三 、查询平均战绩超乎等于85的富有学员的学号、姓名和平均战表
select a.S# , a.Sname , cast(avg(b.score) as decimal(18,2))
avg_score
from Student a , sc b
where a.S# = b.S#
group by a.S# , a.Sname
having cast(avg(b.score) as decimal(18,2)) >= 85
order by a.S#

–3四 、查询课程名称为”数学”,且分数低于60的学员姓名和分数
select sname , score
from Student , SC , Course
where SC.S# = Student.S# and SC.C# = Course.C# and Course.Cname =
N’数学’ and score < 60

–3伍 、查询全体学生的学科及分数情形;
select Student.* , Course.Cname , SC.C# , SC.score
from Student, SC , Course
where Student.S# = SC.S# and SC.C# = Course.C#
order by Student.S# , SC.C#

–3⑥ 、查询任何一门学科成绩在六17分以上的姓名、课程名称和分数;
select Student.* , Course.Cname , SC.C# , SC.score
from Student, SC , Course
where Student.S# = SC.S# and SC.C# = Course.C# and SC.score >=
70
order by Student.S# , SC.C#

–3⑦ 、查询不及格的教程
select Student.* , Course.Cname , SC.C# , SC.score
from Student, SC , Course
where Student.S# = SC.S# and SC.C# = Course.C# and SC.score <
60
order by Student.S# , SC.C#

–3八 、查询课程编号为01且课程成绩在捌10分以上的上学的小孩子的学号和人名;
select Student.* , Course.Cname , SC.C# , SC.score
from Student, SC , Course
where Student.S# = SC.S# and SC.C# = Course.C# and SC.C# = ’01’ and
SC.score >= 80
order by Student.S# , SC.C#

–3九 、求每门科指标学员人数
select Course.C# , Course.Cname , count(*) [学员人数]
from Course , SC
where Course.C# = SC.C#
group by Course.C# , Course.Cname
order by Course.C# , Course.Cname

–40、查询选修”张三”老师所授课程的上学的小孩子中,成绩最高的上学的小孩子新闻及其战绩
–40.1 当最高分唯有一个时
select top 1 Student.* , Course.Cname , SC.C# , SC.score
from Student, SC , Course , Teacher
where Student.S# = SC.S# and SC.C# = Course.C# and Course.T# =
Teacher.T# and Teacher.Tname = N’张三’
order by SC.score desc
–40.2 当最高分出现八个时
select Student.* , Course.Cname , SC.C# , SC.score
from Student, SC , Course , Teacher
where Student.S# = SC.S# and SC.C# = Course.C# and Course.T# =
Teacher.T# and Teacher.Tname = N’张三’ and
SC.score = (select max(SC.score) from SC , Course , Teacher where SC.C#
= Course.C# and Course.T# = Teacher.T# and Teacher.Tname = N’张三’)

–4壹 、查询差异学科成绩同样的学习者的学习者编号、课程编号、学生成绩
–方法1
select m.* from SC m ,(select C# , score from SC group by C# , score
having count(1) > 1) n
where m.C#= n.C# and m.score = n.score order by m.C# , m.score ,
m.S#
–方法2
select m.* from SC m where exists (select 1 from (select C# , score
from SC group by C# , score having count(1) > 1) n
where m.C#= n.C# and m.score = n.score) order by m.C# , m.score ,
m.S#

–4二 、查询每门功成绩最好的前两名
select t.* from sc t where score in (select top 2 score from sc where
C# = T.C# order by score desc) order by t.C# , t.score desc

–4③ 、总计每门课程的学习者选修人数(超过伍位的学科才计算)。供给输出课程号和选修人数,查询结果按人口降序排列,若人数相同,按学科号升序排列
select Course.C# , Course.Cname , count(*) [学生人数]
from Course , SC
where Course.C# = SC.C#
group by Course.C# , Course.Cname
having count(*) >= 5
order by [学生人数] desc , Course.C#

–4④ 、检索至少选修两门课程的学生学号
select student.S# , student.Sname
from student , SC
where student.S# = SC.S#
group by student.S# , student.Sname
having count(1) >= 2
order by student.S#

–4五 、查询选修了上上下下课程的学习者音信
–方法1 基于数据来成功
select student.* from student where S# in
(select S# from sc group by S# having count(1) = (select count(1) from
course))
–方法2 采纳重复否定来成功
select t.* from student t where t.S# not in
(
select distinct m.S# from
(
select S# , C# from student , course
) m where not exists (select 1 from sc n where n.S# = m.S# and n.C# =
m.C#)
)
–方法3 运用重复否定来完成
select t.* from student t where not exists(select 1 from
(
select distinct m.S# from
(
select S# , C# from student , course
) m where not exists (select 1 from sc n where n.S# = m.S# and n.C# =
m.C#)
) k where k.S# = t.S#
)

–4⑥ 、查询各学生的年龄
–46.1 只根据年度来算
select * , datediff(yy , sage , getdate()) [年龄] from student
–46.2 依照出生日期来算,当前月日 < 出生年月的月日则,年龄减一
select * , case when right(convert(varchar(10),getdate(),120),5) <
right(convert(varchar(10),sage,120),5) then datediff(yy , sage ,
getdate()) – 1 else datediff(yy , sage , getdate()) end [年龄] from
student

–4⑦ 、查询本周过生日的学生
select * from student where datediff(week,datename(yy,getdate()) +
right(convert(varchar(10),sage,120),6),getdate()) = 0

–4⑧ 、查询下一周过生日的上学的小孩子
select * from student where datediff(week,datename(yy,getdate()) +
right(convert(varchar(10),sage,120),6),getdate()) = -1

–4玖 、查询本月过生日的学员
select * from student where datediff(mm,datename(yy,getdate()) +
right(convert(varchar(10),sage,120),6),getdate()) = 0

–50、查询下月过生日的学习者
select * from student where datediff(mm,datename(yy,getdate()) +
right(convert(varchar(10),sage,120),6),getdate()) = -1

 

drop table Student,Course,Teacher,SC

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