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惯用sql语句积累-

更新时间: 2014-01-05 02:07:38 责任编辑: Author_N1

 

常用SQL语句积累---

 一、常用的语句格式积累:

Select top 3 * from class order by id desc 表示查询前3条的数据并且按降来排

select distinct 年龄 from class  去除重复行的查询
select top 2 * from class order by newid() 表示随便查询2行数据
select * from class where 年龄=20 or 年龄=19 and 性别='男' 表示先查询年龄等于19 并且是男的 在查询所有年龄等于20的人  先执行AND查询 再执行OR
select * from class where id not in (select id from class1) 表示查询表一中在表2中没有的数据
select * from class where id between 1 and 5 表示查询1到5的数据
select * from class where id not between 1 and 5 表示查询不是1到5的数据
select * from class where 姓名like '刘%' 表示查询刘开头的人
select * from class where 姓名like '%丹%'查询包含丹的人
select * from class where 姓名like '[刘丹]%'查询以刘或者以丹开头的数据
select * from class where 姓名like '[%刘丹]%'查询包含丹或者刘的数据
select * from class where 年龄like '[^1-2]%'查询数据不是以1到2之间开头的
select * from class where 年龄like '[^刘陈]%' 查询不是以刘或者陈开头的数据
select * from class where 工作地址is null 表示查询工作地址不是空值的数据
select * from class where 工作地址is not null 查询不是空植的数据
select * from class where id <> all(select id from class1)表示查询表2在表一中没有的ID数据
select * from class where id = any(select id from class1) 查询表一中和表2相同的ID
elect * from class where (性别not in ('男'))and (not (年龄between 18 and 21)) 
not语句的查询 在条件语句前面加上NOT 
select top 3 * from  class order by id 前面最三个数据
use liudan
select top 3 * from  class order by id desc 最后三个的数据
select ltrim(rtrim(姓名)) from class 里面函数RTRIM代表删除结尾空格数据 外面函数 ltrim 删除前面空格的数据
select 姓名+',' as 姓名,lower(gege) as gege from class    给姓名的每条数据加上 ,; 把gege 列转换为小写
select 姓名+',' as 姓名,upper(gege) as gege from class 后面函数把数据全部转换为大写
select * from class where month(日期)=9 and year(日期)=1993 and day(日期)=9
分别是三个函数 第一个是对指定的日期 月 ,年,日
select 年龄-id as a from class 表示用每一行的数据用年龄-id得到的数据+ - * / 都可以用
select sum(年龄) as a from class  求和
select * from class where 年龄>(select avg(年龄) from class)  求年龄大于平均值的数据
select * from class where 年龄= (select max(年龄) from class) 求年龄最大的、
select * from class where 年龄= (select min(年龄) from class) 年龄最小的人
select count(*) from class 表中数据总条数
select count(年龄) from class 查询年龄不为空的
select sum(年龄) from class where 性别='男' 得到性别为男的的总年龄数
select 年龄,count(*) from class group by 年龄      表示对年龄进行汇总,就是说 对相同年龄的人人数进行汇总 
select 年龄,count(*) from class group by 年龄having 年龄>20 对年龄大于20的才进行汇总
select 年龄,count(*) from class group by 年龄having (年龄 in (20))  年龄在20范围内的汇总
select * from class union select * from class3 将两个表连接到一起来 删除重复的行
select * from class union all select * from class3 保留重复的行
select id from class intersect 
select id from class1    两个表相同的数据 这里因为没有两个相同的表所以只查询ID相同的
select * from class except select * from class3 两个相同的表的不相同的数据
insert into class3 (姓名)values ('dadad')  表示在表中的姓名列插入一个数据  只所以要写是哪个列的数据 是因为不用我插入id了 我门一般设置id是自动生成的 所以再这里要注明;;
update class3 set 工作地址='湖北' where id=2 对ID=2的行 的工作地址的列进行修改
update class3 set 工作地址='湖北' 对所有工作地址的列进行修改
delete top(1) class 删除表中前1条的数据
delete from class3 where id=2删除ID=2的行
select top 3 * from class order by newid() 随机查询3条数据

select * from class order by 名字 collate chinese_prc_cs_as  按音序查询



二、常用的例子收集--

Student(S#,Sname,Sage,Ssex)学生表
Course(C#,Cname,T#) 课程表
SC(S#,C#,score) 成绩表
Teacher(T#,Tname) 教师表

 

问题:
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 whereC#='001') a,(selects#,score
  from SC where C#='002')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 Outer 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 '%';
5、查询没学过“叶平”老师课的同学的学号、姓名;

Student.S#,Student.Sname
    from Student 
    where S# not in (select distinct( SC.S#) fromSC,Course,Teacher where  SC.C#=Course.C# andTeacher.T#=Course.T# and Teacher.Tname='叶平');
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 fromStudent,SC where Student.S#=SC.S# andSC.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“叶平”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# andTeacher.Tname='叶平' groupby S# having count(SC.C#)=(select count(C#) from

Course,Teacher  whereTeacher.T#=Course.T# and Tname='叶平'));
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 (selectStudent.S#,Student.Sname,score ,(select score from SC SC_2 whereSC_2.S#=Student.S# and SC_2.C#='002') score2
  from Student,SC where Student.S#=SC.S# andC#='001') S_2 wherescore2 <score;
9、查询所有课程成绩小于60分的同学的学号、姓名;
  select S#,Sname
  from Student
  where S# not in (select Student.S# from Student,SC whereS.S#=SC.S# and score>60);
10、查询没有学全所有课的同学的学号、姓名;
    select Student.S#,Student.Sname
    from Student,SC
    where Student.S#=SC.S# groupby  Student.S#,Student.Sname having count(C#) <(select count(C#) from Course);
11、查询至少有一门课与学号为“1001”的同学所学相同的同学的学号和姓名;

select S#,Sname from Student,SC whereStudent.S#=SC.S# and C# in select C# from SC where S#='1001';
12、查询至少学过学号为“001”同学所有一门课的其他同学学号和姓名;
    select distinct SC.S#,Sname
    from Student,SC
    where Student.S#=SC.S# andC# in (select C# from SC where S#='001');
13、把“SC”表中“叶平”老师教的课的成绩都更改为此课程的平均成绩;
    update SC set score=(select avg(SC_2.score)
    from SC SC_2
    where SC_2.C#=SC.C# ) fromCourse,Teacher where Course.C#=SC.C# andCourse.T#=Teacher.T# and Teacher.Tname='叶平');
14、查询和“1002”号的同学学习的课程完全相同的其他同学学号和姓名;
    select S# from SC where C# in (select C# from SC where S#='1002')
    group by

S# havingcount(*)=(select count(*) from SC where S#='1002');
15、删除学习“叶平”老师课的SC表记录;
    Delect SC
    from course ,Teacher 
    where Course.C#=SC.C# andCourse.T#= Teacher.T# and Tname='叶平';
16、向SC表中插入一些记录,这些记录要求符合以下条件:没有上过编号“003”课程的同学学号、2
    号课的平均成绩;
    Insert SC select S#,'002',(Select avg(score)
    from SC where C#='002')from Student where S# not in (Select S# from SC where C#='002');
17、按平均成绩从高到低显示所有学生的“数据库”、“企业管理”、“英语”三门的课程成绩,按如下形式显示: 学生ID,,数据库,企业管理,英语,有效课程数,有效平均分
    SELECT S# as 学生ID
        ,(SELECT score FROMSC WHERE SC.S#=t.S# AND C#='004')AS 数据库

,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='001') AS 企业管理
        ,(SELECT score FROMSC WHERE SC.S#=t.S# AND C#='006')AS 英语
        ,COUNT(*) AS 有效课程数,AVG(t.score) AS 平均成绩
    FROM SC AS t
    GROUP BY S#
    ORDER BY avg(t.score) 
18、查询各科成绩最高和最低的分:以如下形式显示:课程ID,最高分,最低分
    SELECT L.C# As 课程ID,L.score AS 最高分,R.scoreAS 最低分
    FROM SC L ,SC AS R
    WHERE L.C# = R.C# and
        L.score = (SELECTMAX(IL.score)
                     FROM SC AS IL,Student AS IM
                     WHERE L.C# = IL.C# and IM.S#=IL.S#
                     GROUP BY IL.C#)
        AND
        R.Score

= (SELECT MIN(IR.score)
                     FROM SC AS IR
                     WHERE R.C# = IR.C#
                 GROUP BY IR.C#
                   );
19、按各科平均成绩从低到高和及格率的百分数从高到低顺序
    SELECT t.C# AS 课程号,max(course.Cname)AS 课程名,isnull(AVG(score),0) AS 平均成绩
        ,100 * SUM(CASEWHEN  isnull(score,0)>=60 THEN 1ELSE 0 END)/COUNT(*) AS 及格百分数
    FROM SC T,Course
    where t.C#=course.C#
    GROUP BY t.C#
    ORDER BY 100 * SUM(CASE WHEN  isnull(score,0)>=60 THEN 1ELSE

0 END)/COUNT(*) DESC
20、查询如下课程平均成绩和及格率的百分数(用"1行"显示):企业管理(001),马克思(002),OO&UML(003),数据库(004
    SELECT SUM(CASE WHEN C# ='001' THENscore ELSE 0 END)/SUM(CASEC# WHEN '001' THEN 1 ELSE 0 END) AS 企业管理平均分
        ,100 * SUM(CASEWHEN C# = '001' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASEWHEN C# = '001' THEN 1 ELSE 0 END

) AS 企业管理及格百分数
        ,SUM(CASEWHEN C# = '002' THEN score ELSE 0END)/SUM(CASEC# WHEN '002' THEN 1 ELSE 0 END) AS 马克思平均分
        ,100 * SUM(CASEWHEN C# = '002' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASEWHEN C# = '002' THEN 1 ELSE 0 END) AS 马克思及格百分数
        ,SUM(CASEWHEN C# = '003' THEN score ELSE 0END)/

SUM(CASE C# WHEN '003' THEN 1 ELSE 0 END) AS UML平均分
        ,100 * SUM(CASEWHEN C# = '003' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASEWHEN C# = '003' THEN 1 ELSE 0 END) AS UML及格百分数
        ,SUM(CASEWHEN C# = '004' THEN score ELSE 0END)/SUM(CASEC# WHEN '004' THEN 1 ELSE 0 END) AS 数据库平均分
        ,100

* SUM(CASE WHEN C# = '004' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASEWHEN C# = '004' THEN 1 ELSE 0 END) AS 数据库及格百分数
  FROM SC
21、查询不同老师所教不同课程平均分从高到低显示
  SELECT max(Z.T#) AS 教师ID,MAX(Z.Tname)AS 教师姓名,C.C# AS 课程ID,MAX(C.Cname) AS 课程名称,AVG(Score)AS 平均成绩
    FROM SC AS T,Course AS C ,Teacher AS Z
    where T.C#=C.C# and C.T#=Z.T#
  GROUP BY C.C#
  ORDER BY AVG(Score) DESC
22、查询如下课程成绩第 3名到第 6 名的学生成绩单:企业管理(001),马克思(002),UML(003),数据库(004
    [学生ID],[学生姓名],企业管理,马克思,UML,数据库,平均成绩
    SELECT  DISTINCT top 3
      SC.S# As 学生学号,
        Student.Sname AS 学生姓名,
      T1.score AS 企业管理,
      T2.score AS 马克思,
      T3.score AS UML,
      T4.score AS 数据库,
      ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) as 总分
      FROM Student,SC  LEFT JOINSC AS T1
                     ON SC.S# = T1.S# AND T1.C# = '001'
            LEFT JOINSC AS T2
                     ON SC.S# = T2.S# AND T2.C# = '002'
            LEFT JOINSC AS T3
                     ON SC.S# =T3.S# AND T3.C# = '003'
            LEFT JOINSC AS T4
                     ON SC.S# = T4.S# AND T4.C# = '004'
      WHERE student.S#=SC.S# and
      ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)
      NOT IN
      (SELECT
            DISTINCT
            TOP 15 WITH TIES
            ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)
      FROM sc
            LEFT JOINsc AS T1
                     ON sc.S# = T1.S# AND T1.C#= 'k1'
            LEFT JOINsc AS T2
                     ON sc.S# = T2.S# AND T2.C# = 'k2'
            LEFT JOINsc AS T3
                     ON sc.S# = T3.S# AND T3.C# = 'k3'
            LEFT JOINsc AS T4
                     ON sc.S# = T4.S# AND T4.C# = 'k4'
      ORDER BY ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) DESC);

23、统计列印各科成绩,各分数段人数:课程ID,课程名称,[100-85],[85-70],[70-60],[ <60]
    SELECT SC.C# as 课程ID,Cname

as 课程名称
        ,SUM(CASEWHEN score BETWEEN 85 AND 100 THEN 1 ELSE 0 END) AS [100- 85]
        ,SUM(CASEWHEN score BETWEEN 70 AND 85 THEN 1 ELSE 0 END) AS [85 -70]
        ,SUM(CASEWHEN score BETWEEN 60 AND 70 THEN 1 ELSE 0 END) AS [70 -60]
        ,SUM(CASEWHEN score < 60 THEN 1 ELSE 0 END) AS [60-]
    FROM SC,Coursewhere SC.C#=Course.C#
    GROUP BY SC.C#,Cname;

24、查询学生平均成绩及其名次
      SELECT 1+(SELECTCOUNT( distinct 平均成绩)
              FROM(SELECT S#,AVG(score) AS 平均成绩
                     FROM SC
                 GROUP BY S#
                 ) AS T1
            WHERE平均成绩 > T2.平均成绩) as 名次,
      S# as 学生学号,平均成绩
    FROM (SELECT S#,AVG(score) 平均成绩
            FROMSC
        GROUP BY S#
        ) AS T2
    ORDER BY 平均成绩 desc;
 
25、查询各科成绩前三名的记录:(不考虑成绩并列情况)
      SELECT t1.S# as 学生ID,t1.C#as 课程ID,Score as 分数
      FROM SC t1
      WHERE score IN (SELECT TOP 3score
              FROMSC
              WHEREt1.C#= C#     ORDER BY score DESC
             )
      ORDER BY t1.C#;
26、查询每门课程被选修的学生数
  select c#,count(S#) from sc group by C#;
27、查询出只选修了一门课程的全部学生的学号和姓名
  select SC.S#,Student.Sname,count(C#) AS 选课数
  from SC ,Student
  where SC.S#=Student.S# group bySC.S# ,Student.Sname having count(C#)=1;
28、查询男生、女生人数
    Select count(Ssex) as 男生人数 fromStudent group by Ssex having Ssex='';
    Select count(Ssex) as 女生人数 fromStudent group by Ssex having Ssex=''
29、查询姓“张”的学生名单
    SELECT Sname FROM Student WHERESname like '%';
30、查询同名同性学生名单,并统计同名人数
  select Sname,count(*) fromStudentgroup by Sname having  count(*)>1;;
31、1981年出生的学生名单(注:Student表中Sage列的类型是datetime)
    select Sname,  CONVERT(char(11),DATEPART(year,Sage)) as age
    from student
    where  CONVERT(char(11),DATEPART(year,Sage))='1981';
32、查询每门课程的平均成绩,结果按平均成绩升序排列,平均成绩相同时,按课程号降序排列
    Select C#,Avg(score) from SC groupby C# order by Avg(score),C# DESC ;
33、查询平均成绩大于85的所有学生的学号、姓名和平均成绩
    select Sname,SC.S# ,avg(score)
    from Student,SC
    where Student.S#=SC.S# groupby SC.S#,Sname having    avg(score)>85;
34、查询课程名称为“数据库”,且分数低于60的学生姓名和分数
    Select Sname,isnull(score,0)
    from Student,SC,Course
    where SC.S#=Student.S# and SC.C#=Course.C#and Course.Cname='数据库'and score <60;
35、查询所有学生的选课情况;
    SELECT SC.S#,SC.C#,Sname,Cname
    FROM SC,Student,Course
    where SC.S#=Student.S# and SC.C#=Course.C#;
36、查询任何一门课程成绩在70分以上的姓名、课程名称和分数;
    SELECT  distinctstudent.S#,student.Sname,SC.C#,SC.score
    FROM student,Sc
    WHERE SC.score>=70 AND SC.S#=student.S#;
37、查询不及格的课程,并按课程号从大到小排列
    select c# from sc where scor e <60 order by C# ;
38、查询课程编号为003且课程成绩在80分以上的学生的学号和姓名;
    select SC.S#,Student.Sname from SC,Student whereSC.S#=Student.S# and Score>80 and C#='003';
39、求选了课程的学生人数
    select count(*) from sc;
40、查询选修“叶平”老师所授课程的学生中,成绩最高的学生姓名及其成绩
    select Student.Sname,score
    from Student,SC,Course C,Teacher
    where Student.S#=SC.S# andSC.C#=C.C# and

C.T#=Teacher.T#and Teacher.Tname='叶平' andSC.score=(select max(score)from SC whereC#=C.C# );
41、查询各个课程及相应的选修人数
    select count(*) from sc group by C#;
42、查询不同课程成绩相同的学生的学号、课程号、学生成绩
  select distinct  A.S#,B.score from SC A ,SC B where A.Score=B.Score and A.C# <>B.C# ;
43、查询每门功成绩最好的前两名
    SELECT t1.S# as 学生ID,t1.C#as 课程ID,Score as 分数
      FROM SC t1
      WHERE score IN (SELECT TOP 2score
              FROMSC
              WHEREt1.C#= C#
            ORDERBY score DESC
             )
      ORDER BY t1.C#;
44、统计每门课程的学生选修人数(超过10人的课程才统计)。要求输出课程号和选修人数,查询结果按人数降序排列,查询结果按人数降序排列,若人数相同,按课程号升序排列 
    select  C# as 课程号,count(*) as 人数


    from sc 
    group  by  C#
    order  by  count(*) desc,c# 
45、检索至少选修两门课程的学生学号
    select  S# 
    from  sc 
    group  by  s#
    having  count(*>  =  2
46
、查询全部学生都选修的课程的课程号和课程名
    select  C#,Cname 
    from  Course 
    where  C#  in  (select c#  from  sc group  by c#) 
47、查询没学过“叶平”老师讲授的任一门课程的学生姓名
    select Sname from Student whereS# not in (select S# from Course,Teacher,SC where Course.T#=Teacher.T#and SC.C#=course.C# and Tname='叶平');
48、查询两门以上不及格课程的同学的学号及其平均成绩
    select S#,avg(isnull(score,0)) fromSC where S# in (select S# from SC where

score <60 group by S# having count(*)>2)groupby S#;
49、检索“004”课程分数小于60,按分数降序排列的同学学号
    select S# from SC where C#='004'and score <60 order by score desc;
50、删除“002”同学的“001”课程的成绩
delete from Sc where S#='001'and C#='001';


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