t_tudent(sid,sname,sage,ssex,sdept) 學生表

t_course(cid,cname,tid) 課程表

t_score( scid,sid,cid,grade) 成績表

t_teacher(tid,tname) 教師表

問題：

1、查詢“001”課程比“002”課程成績高的所有學生的學號;

select t1.sid from

(select sid,grade from t_score where cid = '001') t1,

(select sid,grade from t_score where cid = '002') t2

where t1.grade >t2.grade and t1.sid = t2.sid;

select t2.sid,t2.ca,t2.cb(

select t1.sid,sum(t1.ca) ca,sum(t1.cb) cb

from

(

select sid,

CASE WHEN cid = '001' THEN grade ELSE 0 END ca,

CASE WHEN cid = '002' THEN grade ELSE 0 END cb

from t_score

)t1

GROUP BY sid

)t2

where t2.ca > t2.cb

2、查詢平均成績大于60分的同學的學號和平均成績;

select sid,avg(grade ) from t_score

group by sid

having avg(grade ) >60;

3、查詢所有同學的學號、姓名、選課數、總成績;

select t1.sid,t1.sname,count(t2.cid),sum(grade ) from t_student t1

left join t_score t2

on t1.sid = t2sid

group by t1sid,t1.sname;

4、查詢姓“李”的老師的個數;

select count(distinct(tname)) from t_teacher where tname like '李%';

5、查詢沒學過“葉平”老師課的同學的學號、姓名;

select sid, sname from t_student

where sid not in

(

select distinct(t1.sid) from t_score t1,t_course t2,t_teacher t3

where t1.cid = t2.cid and t3.tid = t2.tid and t3.tname = '葉平'

);

6、查詢學過“001”并且也學過編號“002”課程的同學的學號、姓名;

select t0.sid,t0.sname from t_student t0, t_score t1

where t0.sid = t1.sid and t1.cid = '001'

and exists

(

select * from t_score t2 where t2.sid = t1.sid and t2.cid = '002'

);

7、查詢學過“葉平”老師所教的所有課的同學的學號、姓名;

select sid,sname from t_student

where sid in

(

select sid from t_score t1 ,t_course t2,t_teacher t3

where t1.cid=t2.cid

and t3.tid=t2.tid

and t3.tname = '葉平'

group by sid

having count(t1.cid)=(

select count(cid) from t_course t1,t_teacher t2

where t2.tid=t1.tid and t2.tname = '葉平'

)

);

8、查詢“001”課程比“002”課程成績高的所有同學的學號、姓名;

Select sid,sname from

(

select t1.sid,t1.sname,t2.grade ,

(

select grade from t_score t3

where t3.sid = t1.sid and t3.cid = '002'

) grade2

from t_student t1, t_score t2

where t1sid = t2.sid and t2.cid = '001'

) S_2

where grade 2 < grade ;

9、查詢所有課程成績小于60分的同學的學號、姓名;

select sid,sname from t_student

where sid not in

(

select t1.sid from t_student t1, t_score t2

where t1.sid = t2.sid and t2.grade >60

);

10、查詢沒有學全所有課的同學的學號、姓名;

select t1.sid,t1.sname from Student t1, t_score t2

where t1.sid = t2.sid

group by t1.sid,t1.sname

having count(t2.cid) < (select count(cid) from t_course);

11、查詢至少有一門課與學號為“1001”的同學所學相同的同學的學號和姓名;

select sid,sname from t_student t1, t_score t2

where t1.sid = t2.sid

and cid in (select cid from t_score where sid = '1001');

12、查詢至少學過學號為“001”同學所有一門課的其他同學學號和姓名;

select distinct t2.sid,t1.sname from t_student t1, t_score t2

where t1.sid = t2.sid

and cid in (select cid from t_score where sid = '001');

13、把“ t_score”表中“葉平”老師教的課的成績都更改為此課程的平均成績;

update t_score t4 set grade =(select avg( t3.grade ) from t_score t3 where t3.cid= t4.cid )

from t_course t1,t_teacher t2

where t1.cid = t4.cid

and t1.tid = t2.tid

and t2.tname = '葉平');

14、查詢和“1002”號的同學學習的課程完全相同的其他同學學號和姓名;

select sid from t_score

where cid in (select cid from t_score where sid = '1002')

group by sid

having count(*)=(select count(*) from t_score where sid = '1002');

15、刪除學習“葉平”老師課的 t_score表記錄;

delect t_score from t_course t1 ,t_teacher t2

Where t1.cid = t2.cid

and t1.tid = t2.tid

and t2.tname = '葉平';

16、向 t_score表中插入一些記錄，這些記錄要求符合以下條件：沒有上過編號“003”課程的同學學號、2、

號課的平均成績;

insert t_score

select sid,'002',(Select avg(grade ) from t_score where cid = '002')

from t_student

where sid not in (Select sid from t_score where cid = '002');

17、按平均成績從高到低顯示所有學生的“數據庫”、“企業(yè)管理”、“英語”三門的課程成績，按如下形式顯示： 學生ID,,數據庫,企業(yè)管理,英語,有效課程數,有效平均分

SELECT sid as 學生ID,

(SELECT grade FROM t_score WHERE sid=t.sid AND cid='004') AS 數據庫,

(SELECT grade FROM t_score WHERE sid=t.sid AND cid='001') AS 企業(yè)管理,

(SELECT grade FROM t_score WHERE sid=t.sid AND cid='006') AS 英語,

COUNT(*) AS 有效課程數,

AVG(t.grade ) AS 平均成績

FROM t_score AS t

GROUP BY sid

ORDER BY avg(t.grade )

18、查詢各科成績最高和最低的分：以如下形式顯示：課程ID，最高分，最低分

SELECT t1.cid As 課程ID,t1.grade AS 最高分,t2.grade AS 最低分

FROM t_score t1 , t_score t2

WHERE t1.cid = t2.cid

and t1.grade = (

SELECT MAX(tt1.grade ) FROM t_score tt1,t_student tt2

WHERE t1.cid = tt1.cid and tt2.sid = tt1.sid

GROUP BY tt1.cid

)

AND t2.grade = (

SELECT MIN(tt3.grade ) FROM t_score AS tt3

WHERE t2.cid = tt3.cid GROUP BY tt2.cid

);

19、按各科平均成績從低到高和及格率的百分數從高到低順序

SELECT t.cid AS 課程號,max(course.cname)AS 課程名,isnull(AVG(grade ),0) AS 平均成績 ,

100 * SUM(CASE WHEN isnull(grade ,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) AS 及格百分數

FROM t_score t1,t_course t2

where t1.cid = t2.cid

GROUP BY t1.cid

ORDER BY 100 * SUM(CASE WHEN isnull(grade ,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) DESC

20、查詢如下課程平均成績和及格率的百分數(用"1行"顯示): 企業(yè)管理(001)，馬克思(002)，OO&UML (003)，數據庫(004)

SELECT

SUM(

CASE WHEN cid = '001'

THEN grade ELSE 0 END)/SUM(CASE cid WHEN '001'

THEN 1 ELSE 0 END

) AS 企業(yè)管理平均分 ,

100 * SUM(

CASE WHEN cid = '001' AND grade >= 60

THEN 1 ELSE 0 END)/SUM(CASE WHEN cid = '001'

THEN 1 ELSE 0 END

) AS 企業(yè)管理及格百分數 FROM t_score

21、查詢不同老師所教不同課程平均分從高到低顯示

SELECT max(t3.tid) AS 教師ID,MAX(t3.tname) AS 教師姓名,

T2.cid AS 課程ID,MAX(t2.cname) AS 課程名稱,AVG(grade ) AS 平均成績

FROM t_score AS t1,t_course AS t2 ,t_teacher AS t3

where t1.cid = t2.cid and t2.tid = t3.tid

GROUP BY t2.cid

ORDER BY AVG(grade ) DESC ;

22、查詢如下課程成績第 3 名到第 6 名的學生成績單：企業(yè)管理(001)，馬克思(002)，UML (003)，數據庫(004)

[學生ID],[學生姓名],企業(yè)管理,馬克思,UML,數據庫,平均成績

SELECT DISTINCT top 3 t_score.sid As 學生學號,Student.Sname AS 學生姓名 ,

T1.grade AS 企業(yè)管理, T2.grade AS 馬克思, T3.grade AS UML,

T4.grade AS 數據庫,ISNULL(T1.grade ,0) + ISNULL(T2.grade ,0) + ISNULL(T3.grade ,0) + ISNULL(T4.grade ,0) as 總分

FROM Student, t_score

LEFT JOIN t_score AS T1

ON t_score.sid = T1.sid AND T1.cid = '001'

LEFT JOIN t_score AS T2

ON t_score.sid = T2.sid AND T2.cid = '002'

LEFT JOIN t_score AS T3

ON t_score.sid = T3.sid AND T3.cid = '003'

LEFT JOIN t_score AS T4

ON t_score.sid = T4.sid AND T4.cid = '004'

WHERE student.sid= t_score.sid

and ISNULL(T1.grade ,0) + ISNULL(T2.grade ,0) + ISNULL(T3.grade ,0) + ISNULL(T4.grade ,0)

NOT IN (

SELECT DISTINCT TOP 15 WITH TIES ISNULL(T1.grade ,0) + ISNULL(T2.grade ,0) + ISNULL(T3.grade ,0) + ISNULL(T4.grade ,0)

FROM t_score

LEFT JOIN t_score AS T1

ON t_score.sid = T1.sid AND T1.cid = 'k1'

LEFT JOIN t_score AS T2

ON t_score.sid = T2.sid AND T2.cid = 'k2'

LEFT JOIN t_score AS T3

ON t_score.sid = T3.sid AND T3.cid = 'k3'

LEFT JOIN t_score AS T4

ON t_score.sid = T4.sid AND T4.cid = 'k4'

ORDER BY ISNULL(T1.grade ,0) + ISNULL(T2.grade ,0) + ISNULL(T3.grade ,0) + ISNULL(T4.grade ,0) DE t_score

);

23、統(tǒng)計列印各科成績,各分數段人數:課程ID,課程名稱,[100-85],[85-70],[70-60],[ <60]

SELECT t1.cid as 課程ID, t2.cname as 課程名稱,

SUM(CASE WHEN t1.grade BETWEEN 85 AND 100 THEN 1 ELSE 0 END) AS [100 - 85],

SUM(CASE WHEN t1.grade BETWEEN 70 AND 85 THEN 1 ELSE 0 END) AS [85 - 70],

SUM(CASE WHEN t1.grade BETWEEN 60 AND 70 THEN 1 ELSE 0 END) AS [70 - 60],

SUM(CASE WHEN t1.grade < 60 THEN 1 ELSE 0 END) AS [60 -]

FROM t_score t1,t_course t2 where t1.cid = t2.cid

GROUP BY t1.cid,t2.cname;

24、查詢學生平均成績及其名次

SELECT

1+(

SELECT COUNT( distinct avggrade )

FROM (

SELECT sid,AVG(grade ) AS avggrade FROM t_score GROUP BY sid

) AS T1 WHERE avggrade > T2.avggrade ) as 名次,

sid as 學生學號,

avggrade

FROM (

SELECT sid,AVG(grade )as avggrade FROM t_score GROUP BY sid

) AS T2

ORDER BY avggrade desc;

25、查詢各科成績前三名的記錄:(不考慮成績并列情況)

SELECT t1.sid as 學生ID,t1.cid as 課程ID,grade as 分數

FROM t_score t1 WHERE grade IN (

SELECT TOP 3 grade FROM t_score t2 WHERE t1.cid = t2.cid ORDER BY grade DESC

)

ORDER BY t1.cid;

26、查詢每門課程被選修的學生數

select cid,count(sid) from t_score group by cid;

27、查詢出只選修了一門課程的全部學生的學號和姓名

select t1.sid,t2.sname,count(t1.cid) AS 選課數 from t_score t1,t_student t2

where t1.sid=t2.sid

group by t1.sid ,t2.sname

having count(t1.cid)=1;

28、查詢男生、女生人數

Select count(ssex) as 男生人數 from t_student group by ssex having ssex='男';

Select count(ssex) as 女生人數 from t_student group by ssex having ssex='女';

29、查詢姓“張”的學生名單

SELECT sname FROM t_student WHERE sname like '張%';

30、查詢同名同性學生名單，并統(tǒng)計同名人數

select sname,count(*) from t-student group by sname having count(*)>1;

31、1981年出生的學生名單(注：Student表中Sage列的類型是datetime)

select sname, CONVERT(char(11),DATEPART(year,sage)) as age

from t_tudent

where CONVERT(char(11),DATEPART(year,Sage))='1981';

32、查詢每門課程的平均成績，結果按平均成績升序排列，平均成績相同時，按課程號降序排列

Select cid,Avg(grade ) from t_score group by cid order by Avg(grade ),cid DESC

33、查詢平均成績大于85的所有學生的學號、姓名和平均成績

select t1.sname, t2.sid ,avg(t2.grade ) from t_student t1, t_score t2

where t1.sid=t2.sid group by t2.sid,t1.sname

having avg(t2.grade )>85;

34、查詢課程名稱為“數據庫”，且分數低于60的學生姓名和分數

Select t1.sname,isnull(t2.grade ,0) from t_student t1, t_score t2,t_course t3

where t2.sid = t1.sid and t2.cid = t3.cid

and t3.cname='數據庫'and t2.grade <60;

35、查詢所有學生的選課情況;

SELECT t1.sid, t1.cid,t2.sname,t3.cname FROM t_score t1,t_student t2,t_course t3

where t1.sid = t2.sid and t1.cid = t3.cid ;

36、查詢任何一門課程成績在70分以上的姓名、課程名稱和分數;

SELECT distinct t1.sid,t1.sname,t2.cid, t2.grade FROM t_student t1, t_score t2

WHERE t2.grade >=70 AND t2.sid = t1.sid;

37、查詢不及格的課程，并按課程號從大到小排列

select cid from t_score where grade < 60 order by cid ;

38、查詢課程編號為003且課程成績在80分以上的學生的學號和姓名;

select t1.sid,t2.sname from t_score t1,t_student t2

where t1.sid = t2.sid and t1.grade > 80 and t1.cid = '003';

39、求選了課程的學生人數

select count(*) from t_score;

40、查詢選修“葉平”老師所授課程的學生中，成績最高的學生姓名及其成績

select t1.sname,t2.grade from t_student t1, t_score t2,t_course t3,t_teacher t4

where t1.sid = t2.sid

and t2.cid = t3.cid

and t3.tid = t4.tid

and t4.Tname = '葉平'

and t2.grade = (select max(grade )from t_score where cid=t3.cid );

41、查詢各個課程及相應的選修人數

select count(*) from t_score group by cid

42、查詢不同課程成績相同的學生的學號、課程號、學生成績

select distinct t1.sid,t2.grade from t_score t1 , t_score t2

where t1.grade = t2.grade and t1.cid <>t2.cid ;

43、查詢每門功成績最好的前兩名

SELECT t1.sid as 學生ID,t1.cid as 課程ID,grade as 分數 FROM t_score t1

WHERE grade IN (

SELECT TOP 2 grade FROM t_score

WHERE t1.cid = cid ORDER BY grade DESC

)

ORDER BY t1.cid;

44、統(tǒng)計每門課程的學生選修人數(超過10人的課程才統(tǒng)計)。要求輸出課程號和選修人數，查詢結果按人數降序排列，查詢結果按人數降序排列，若人數相同，按課程號升序排列

select cid as 課程號,count(*) as 人數 from t_score

group by cid

order by count(*) desc,cid

45、檢索至少選修兩門課程的學生學號

select sid from t_score group by sid having count(*) > = 2

46、查詢全部學生都選修的課程的課程號和課程名

select cid,cname from t_course where cid in (select cid from t_score group by cid)

47、查詢沒學過“葉平”老師講授的任一門課程的學生姓名

select sname from t_student

where sid not in (

select sid from t_course t1,t_teacher t2, t_score t3

where t1.tid = t2.tid

and t3.cid =t 1.cid

and t2.tname = '葉平'

);

48、查詢兩門以上不及格課程的同學的學號及其平均成績

select sid,avg(isnull(grade ,0)) from t_score

where sid in (

select sid from t_score

where grade <60 group by sid having count(*)>2

)

group by sid;

49、檢索“004”課程分數小于60，按分數降序排列的同學學號

select sid from t_score where cid='004'and grade <60 order by grade desc;

50、刪除“002”同學的“001”課程的成績

delete from t_score where sid='001'and cid = '001';

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