SQL 經典五十道題
阿新 • • 發佈：2019-01-13
--1.學生表
Student(S,Sname,Sage,Ssex) --S 學生編號,Sname 學生姓名,Sage 出生年月,Ssex 學生性別
--2.課程表
Course(C,Cname,T) --C --課程編號,Cname 課程名稱,T 教師編號
--3.教師表
Teacher(T,Tname) --T 教師編號,Tname 教師姓名
--4.成績表
SC(S,C,score) --S 學生編號,C 課程編號,score 分數
*/
--建立測試資料
create table Student(S varchar(10),Sname varchar(10),Sage datetime,Ssex nvarchar --1、查詢"01"課程比"02"課程成績高的學生的資訊及課程分數
SELECT a. ,c.
from
(select
a.*
from
(SELECT * from sc WHERE sc.C in('01'))a
left JOIN(SELECT * from sc where sc.C in('02'))b
ON a.s =b.s
where a.score>b.score ) a ,student c
where a.s =c.s;
--2、查詢"01"課程比"02"課程成績低的學生的資訊及課程分數
SELECT a. ,c.
FROM
(SELECT a.*
FROM
(SELECT * FROM sc WHERE sc.C in('01'))a
LEFT JOIN(SELECT * FROM sc WHERE sc.C in('02'))b
ON a.s =b.s WHERE a.score<b.score) a,student c
WHERE a.s =c.s
--3、查詢平均成績大於等於60分的同學的學生編號和學生姓名和平均成績
SELECT
b.s
,c.Sname
,b.avgscore
FROM
(SELECT
a.s s
, avg(a.score) avgscore
FROM sc a
GROUP BY a.s) b
,student c
WHERE
b.avgscore>60 AND c.s =b.s
--4、查詢平均成績小於60分的同學的學生編號和學生姓名和平均成績
SELECT
b.s
,c.Sname
,b.avgscore
FROM
(SELECT
a.s s
, avg(a.score) avgscore
FROM sc a
GROUP BY a.s) b
,student c
WHERE
b.avgscore<60 AND c.s =b.s
--5、查詢所有同學的學生編號、學生姓名、選課總數、所有課程的總成績
SELECT
b.s
,c.Sname
,b.num
,b.sumscore
FROM
(SELECT
a.s s
,COUNT(a.c) num
,SUM(a.score) sumscore
FROM
sc a
GROUP BY a.s) b
,student c
WHERE b.s =c.s
--6、查詢"李"姓老師的數量
SELECT
COUNT(a.Tname)
FROM
(SELECT
Tname Tname
FROM
teacher
WHERE
Tname LIKE '李%') a
--7、查詢學過"張三"老師授課的同學的資訊
SELECT
d.*
FROM
student d
,sc e
WHERE
e.S =d.S
AND
e.C=
(SELECT
b.C
FROM
teacher a
,course b
WHERE
a.T =b.T AND a.Tname='張三')
--8、查詢沒學過"張三"老師授課的同學的資訊
SELECT
a.*
FROM
student a
WHERE
a.S NOT in
(SELECT
b.S
FROM
sc a
,student b
WHERE
a.S=b.S AND
a.C =
(SELECT
b.c
FROM
teacher a
,course b
WHERE
a.T =b.T AND a.Tname ='張三'))
--9、查詢學過編號為"01"並且也學過編號為"02"的課程的同學的資訊
SELECT
*
FROM
sc a,
sc b,
student c
WHERE
a.S =b.S AND a.C='01' and b.C='02'
AND c.S =a.S
--10、查詢學過編號為"01"但是沒有學過編號為"02"的課程的同學的資訊
SELECT
*
FROM
student a
WHERE
a.S in
(
SELECT
DISTINCT(sc.s)
FROM
sc
WHERE
sc.S
NOT
in(
SELECT S
FROM sc
WHERE
sc.C in('02')
GROUP BY
sc.S)
)
--11、查詢沒有學全所有課程的同學的資訊
SELECT
b.*
FROM
student b
WHERE
b.S in
(
SELECT
a.s
FROM
(SELECT
a.S s
,COUNT(a.C) NUM
FROM
sc a
GROUP BY
a.s) a
WHERE
a.NUM<3
)
--12、查詢至少有一門課與學號為"01"的同學所學相同的同學的資訊
SELECT
e.*
FROM
student e
WHERE
e.S in
(SELECT
DISTINCT(c.s)
FROM
student c
,sc d
WHERE
c.s=d.s
AND
d.C in
(SELECT
b.c
FROM
student a
,sc b
WHERE
a.s =b.s AND a.s ='01'
)
)
--13、查詢和"01"號的同學學習的課程完全相同的其他同學的資訊
SELECT
a.c
FROM
sc a
WHERE
a.S ='01'
---
SELECT
*
FROM
(SELECT
a.*
,COUNT(b.c) num
FROM
student a
,sc b
WHERE
a.s=b.S
GROUP BY
b.S
) a
WHERE
a.num=3 AND a.s <> '01'
--14、查詢沒學過"張三"老師講授的任一門課程的學生姓名
SELECT
*
FROM
student a
WHERE
a.S NOT in
(
SELECT
b.S
FROM
(
SELECT
b.c
,b.Cname
FROM
teacher a
,course b
WHERE
a.T=b.T
AND
a.Tname='張三'
) a
,sc b
WHERE
a.c=b.C
)
--15、查詢兩門及其以上不及格課程的同學的學號，姓名及其平均成績
SELECT
b.S
,b.Sname
,a.avgscore
FROM
(SELECT
AVG(score) avgscore
,s S
FROM
sc
WHERE
sc.score<60
GROUP BY
s
HAVING COUNT(s)>=2) a
,student b
WHERE
a.S=b.S
--16、檢索"01"課程分數小於60，按分數降序排列的學生資訊
SELECT
b.*
FROM
(SELECT
a.s s
FROM
sc a
WHERE
a.C ='01'
AND
a.score<60
ORDER BY a.score DESC
) a
,student b
WHERE
a.s=b.S
--17、按平均成績從高到低顯示所有學生的所有課程的成績以及平均成績
SELECT
*
FROM
(SELECT
b.S
,b.C
,b.score
,c.avgscore
FROM
sc b
LEFT JOIN
(SELECT
a.S
,AVG(a.score) avgscore
FROM
sc a
GROUP BY a.S) c
ON c.S =b.S) a
,student b
WHERE
a.S =b.S
ORDER BY avgscore DESC
--18、查詢各科成績最高分、最低分和平均分：以如下形式顯示：課程ID，課程name，最高分，最低分，平均分，及格率，中等率，優良率，優秀率
--及格為>=60，中等為：70-80，優良為：80-90，優秀為：>=90
SELECT
a.C
,b.Cname
,MAX(a.score)
,MIN(a.score)
,AVG(a.score)
,(SELECT COUNT(1) FROM sc WHERE sc.C=b.C and score>60)/(SELECT COUNT(1)FROM sc WHERE sc.C=b.c ) jigelv
FROM sc a ,course b
WHERE a.C =b.C
GROUP BY
a.C
SELECT
a.C
,a.Cname
,MAX(b.score)
,MIN(b.score)
,CAST(AVG(b.score) AS DECIMAL(18,2)) pingqunfen
,CAST((SELECT COUNT(1) FROM sc WHERE sc.C=a.C AND sc.score>60)/
(SELECT COUNT(1) FROM sc WHERE sc.C =a.C) AS DECIMAL(18,2)) jigelv
,CAST((SELECT COUNT(1) FROM sc WHERE sc.C =a.c AND sc.score>=70 AND sc.score<80)/
(SELECT COUNT(1) FROM sc WHERE sc.c =a.c) AS DECIMAL (18,2)) youlianlv
FROM
course a,sc b
WHERE
a.C=b.C
GROUP BY a.C,a.Cname
ORDER BY a.C DESC
--19、按各科成績進行排序，並顯示排名
SELECT
c.s
,c.sname
,b.cname
,a.score
,(SELECT COUNT(1) FROM sc WHERE sc.C=a.c AND sc.score > a.score)+1 mc
FROM
sc a ,course b,student c
WHERE a.c='01'
AND a.c=b.c
AND a.s=c.s
ORDER BY mc
SELECT
c.s
,c.sname
,b.cname
,a.score
,(SELECT COUNT(1) FROM sc WHERE sc.C=a.c AND sc.score > a.score)+1 mc
FROM
sc a ,course b,student c
WHERE a.c='02'
AND a.c=b.c
AND a.s=c.s
ORDER BY mc
SELECT
c.s
,c.sname
,b.cname
,a.score
,(SELECT COUNT(1) FROM sc WHERE sc.C=a.c AND sc.score > a.score)+1 mc
FROM
sc a ,course b,student c
WHERE a.c='03'
AND a.c=b.c
AND a.s=c.s
ORDER BY mc
--20、查詢學生的總成績並進行排名
SELECT
b.s
,b.sumscore
,@rownum:[email protected] +1 AS rownum
FROM
(SELECT
a.s s
,SUM(a.score) sumscore
FROM
sc a
GROUP BY
a.S
ORDER BY sumscore DESC
) as b
,(SELECT @rownum:=0)r
--21、查詢不同老師所教不同課程平均分從高到低顯示
SELECT
c.Tname
,b.Cname
,AVG(a.score)
FROM
sc a
,course b
,teacher c
WHERE
a.C =b.C
AND b.T =c.T
GROUP BY a.C
ORDER BY AVG(a.score) DESC
--22、查詢所有課程的成績第2名到第3名的學生資訊及該課程成績
SELECT
a.*
,b.*
FROM
(SELECT b.s ,b.C ,b.score
,(SELECT COUNT(*) FROM sc a WHERE a.c='01'AND a.score>b.score)+1 mc
FROM sc b WHERE b.c='01' HAVING mc BETWEEN 2 AND 3
UNION ALL
SELECT b.s ,b.C ,b.score
,(SELECT COUNT(*) FROM sc a WHERE a.c='02'AND a.score>b.score)+1 mc
FROM sc b WHERE b.c='02' HAVING mc BETWEEN 2 AND 3
UNION ALL
SELECT b.s ,b.C ,b.score
,(SELECT COUNT(*) FROM sc a WHERE a.c='03'AND a.score>b.score)+1 mc
FROM sc b WHERE b.c='03' HAVING mc BETWEEN 2 AND 3
) a
,student b
WHERE
a.s =b.s
--23、統計各科成績各分數段人數：課程編號,課程名稱,[100-85],[85-70],[70-60],[0-60]及所佔百分比
SELECT
a.*
FROM
(SELECT
c.Cname
,(SELECT COUNT(*)FROM sc a WHERE a.score>85 AND a.C=b.c AND c.c=a.C AND a.C='01') '85以上'
,(SELECT COUNT(*)FROM sc a WHERE a.score<85 AND a.C=b.c AND c.c=a.C AND a.score>70 AND a.C='01') '[70_85]'
,(SELECT COUNT(*)FROM sc a WHERE a.score>70 AND a.C=b.c AND c.c=a.C AND a.score>60 AND a.C='01') '[60_70]'
,(SELECT COUNT(*)FROM sc a WHERE a.score<60