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、查詢平均成績大於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”並且也學過編號“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於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：企業管理(001)，馬克思(002)，UML (003)，數據庫(004)
[學生ID],[學生姓名],企業管理,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:(不考慮成績並列情況)
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，並統計同名人數
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、查詢平均成績大於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”，且分數低於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，並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、統計每門課程的學生選修人數(超過10人的課程才統計)。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”課程分數小於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';
