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  • 当前位置: 小苹果范文网 > 探索 > 正文

    sql查询语句练习_

    时间:2018-07-12 20:00:45 来源:小苹果范文网 本文已影响 小苹果范文网手机站

    最近在学习SQL嘛,所以各个地方找题目来练手,毕竟现在能离得开数据库么?

    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 where C#='001') a,(select s#,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 '李%';

    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#) from SC,Course,Teacher where SC.C#=Course.C# and Teacher.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 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# and SC_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# and Teacher.Tname='叶平' group by S# having count(SC.C#)=(select count(C#) from

    Course,Teacher where Teacher.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 (select Student.S#,Student.Sname,score ,(select score from SC SC_2 where SC_2.S#=Student.S# and SC_2.C#='002') score2

    from Student,SC where Student.S#=SC.S# and C#='001') S_2 where score2 《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 where S.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# group by 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 where Student.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# and C# 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# ) from Course,Teacher where Course.C#=SC.C# and Course.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# having count(*)=(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# and Course.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 FROM SC 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 FROM SC 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.score AS 最低分

    FROM SC L ,SC AS R

    WHERE L.C# = R.C# and

    L.score = (SELECT MAX(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(CASE WHENisnull(score,0)》=60 THEN 1 ELSE 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 WHENisnull(score,0)》=60 THEN 1 ELSE

    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' THEN score ELSE 0 END)/SUM(CASE C# WHEN '001' THEN 1 ELSE 0 END) AS 企业管理平均分

    ,100 * SUM(CASE WHEN C# = '001' AND score 》= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '001' THEN 1 ELSE 0 END

    ) AS 企业管理及格百分数

    ,SUM(CASE WHEN C# = '002' THEN score ELSE 0 END)/SUM(CASE C# WHEN '002' THEN 1 ELSE 0 END) AS 马克思平均分

    ,100 * SUM(CASE WHEN C# = '002' AND score 》= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '002' THEN 1 ELSE 0 END) AS 马克思及格百分数

    ,SUM(CASE WHEN C# = '003' THEN score ELSE 0 END)/

    SUM(CASE C# WHEN '003' THEN 1 ELSE 0 END) AS UML平均分

    ,100 * SUM(CASE WHEN C# = '003' AND score 》= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '003' THEN 1 ELSE 0 END) AS UML及格百分数

    ,SUM(CASE WHEN C# = '004' THEN score ELSE 0 END)/SUM(CASE C# 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(CASE WHEN 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

    SELECTDISTINCT 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 JOIN SC AS T1

    ON SC.S# = T1.S# AND T1.C# = '001'

    LEFT JOIN SC AS T2

    ON SC.S# = T2.S# AND T2.C# = '002'

    LEFT JOIN SC AS T3

    ON SC.S# =T3.S# AND T3.C# = '003'

    LEFT JOIN SC 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 JOIN sc AS T1

    ON sc.S# = T1.S# AND T1.C#= 'k1'

    LEFT JOIN sc AS T2

    ON sc.S# = T2.S# AND T2.C# = 'k2'

    LEFT JOIN sc AS T3

    ON sc.S# = T3.S# AND T3.C# = 'k3'

    LEFT JOIN sc 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(CASE WHEN score BETWEEN 85 AND 100 THEN 1 ELSE 0 END) AS [100 - 85]

    ,SUM(CASE WHEN score BETWEEN 70 AND 85 THEN 1 ELSE 0 END) AS [85 - 70]

    ,SUM(CASE WHEN score BETWEEN 60 AND 70 THEN 1 ELSE 0 END) AS [70 - 60]

    ,SUM(CASE WHEN 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+(SELECT COUNT( 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

    FROM SC

    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 3 score

    FROM SC

    WHERE t1.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 by SC.S# ,Student.Sname having count(C#)=1;

    28、查询男生、女生人数

    Select count(Ssex) as 男生人数 from Student group by Ssex having Ssex='男';

    Select count(Ssex) as 女生人数 from Student group by Ssex having Ssex='女';

    29、查询姓“张”的学生名单

    SELECT Sname FROM Student WHERE Sname like '张%';

    30、查询同名同性学生名单,并统计同名人数

    select Sname,count(*) from Studentgroup by Sname havingcount(*)》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

    whereCONVERT(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 group by 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# group by SC.S#,Sname havingavg(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;

    SELECTdistinct student.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 where SC.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# and SC.C#=C.C# and

    C.T#=Teacher.T# and Teacher.Tname='叶平' and SC.score=(select max(score)from SC where C#=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 2 score

    FROM SC

    WHERE t1.C#= C#

    ORDER BY 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

    groupby C#

    orderbycount(*) desc,c#

    45、检索至少选修两门课程的学生学号

    select S#

    from sc

    groupby s#

    havingcount(*) 》=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 groupby 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 where S# 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)) from SC where S# in (select S# from SC where

    score 《60 group by S# having count(*)》2)group by 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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