-------------------欢迎交流，第一遍过这些题目。网上提供的数据源各有不同，谨慎食用。----------------
-------------------如需要数据源，留言----------------
--1.查询" 01 "课程比" 02 "课程成绩高的学生的信息及课程分数
SELECT
T1.*,T2.[01课程分数],T2.[02课程分数]
FROM
dbo.Student T1
INNER JOIN
(
SELECT
T1.SId,T1.score AS N\'01课程分数\',T2.score AS N\'02课程分数\'
FROM
(SELECT * FROM dbo.SC WHERE CId =N\'01\' ) AS T1
INNER JOIN (SELECT * FROM dbo.SC WHERE CId =N\'02\' ) AS T2
ON T2.SId = T1.SId
WHERE
T1.score>T2.score
) AS T2
ON T2.SId = T1.SId
--1.1 查询同时存在" 01 "课程和" 02 "课程的情况
SELECT
T1.*
FROM
dbo.Student T1
INNER JOIN
(
SELECT
T1.SId
FROM
(SELECT * FROM dbo.SC WHERE CId =N\'01\' ) AS T1
INNER JOIN (SELECT * FROM dbo.SC WHERE CId =N\'02\' ) AS T2
ON T2.SId = T1.SId
) AS T2
ON T2.SId = T1.SId
--1.2 查询存在" 01 "课程但可能不存在" 02 "课程的情况(不存在时显示为 null )
SELECT
T2.SId,T1.Sname,t1.Sage,T1.Ssex
FROM
dbo.Student T1
FULL OUTER JOIN
(
SELECT
T1.SId
FROM
(SELECT * FROM dbo.SC WHERE CId =N\'01\' ) AS T1
INNER JOIN (
--不存在02课程
SELECT DISTINCT SId FROM dbo.SC T1
WHERE NOT EXISTS
(SELECT SId FROM dbo.SC T2 WHERE T2.CId = N\'02\' AND T1.SId = T2.SId )
) AS T2
ON T2.SId = T1.SId
) AS T2
ON T2.SId = T1.SId
ORDER BY T2.SId DESC
--1.3 查询不存在" 01 "课程但存在" 02 "课程的情况
SELECT
T2.SId,T1.Sname,t1.Sage,T1.Ssex
FROM
dbo.Student T1
INNER JOIN
(
SELECT
T1.SId
FROM
(SELECT * FROM dbo.SC WHERE CId =N\'02\' ) AS T1
INNER JOIN (
--不存在01课程
SELECT DISTINCT SId FROM dbo.SC T1
WHERE NOT EXISTS
(SELECT SId FROM dbo.SC T2 WHERE T2.CId = N\'01\' AND T1.SId = T2.SId )
) AS T2
ON T2.SId = T1.SId
) AS T2
ON T2.SId = T1.SId
--2.查询平均成绩大于等于 60 分的同学的学生编号和学生姓名和平均成绩
SELECT
T1.SId
,T1.Sname
,AVG(T2.score) AS N\'平均成绩\'
FROM
dbo.Student T1
INNER JOIN dbo.SC T2
ON T2.SId = T1.SId
GROUP BY
T1.SId
,T1.Sname
HAVING
AVG(T2.score) >= 60.00
--3.查询在 SC 表存在成绩的学生信息
SELECT
DISTINCT T1.*
FROM
dbo.Student AS T1
INNER JOIN dbo.SC AS T2
ON T1.SId = T2.SId
--4.查询所有同学的学生编号、学生姓名、选课总数、所有课程的总成绩(没成绩的显示为 null )
;WITH tbl_Course AS (
SELECT
T2.SId
,COUNT(T2.CId) AS N\'选课总数\'
,SUM(T2.score) AS N\'课程总成绩\'
FROM
dbo.Course AS T1
LEFT OUTER JOIN dbo.SC AS T2
ON T1.CId = T2.CId
GROUP BY
T2.SId
)
SELECT
T1.*
,T2.选课总数
,T2.课程总成绩
FROM dbo.Student AS T1
LEFT OUTER JOIN tbl_Course AS T2
ON T1.SId = T2.SId
--4.1 查有成绩的学生信息
SELECT
DISTINCT T1.*
FROM
dbo.Student AS T1
INNER JOIN dbo.SC AS T2
ON T1.SId = T2.SId
--5.查询「李」姓老师的数量
SELECT
COUNT(*) AS N\'李姓老师的数量\'
FROM
dbo.Teacher
WHERE
Tname LIKE N\'李%\'
--6.查询学过「张三」老师授课的同学的信息
SELECT
T1.*
FROM
dbo.Student AS T1
INNER JOIN (
SELECT
T1.SId
FROM
dbo.SC AS T1
INNER JOIN (
SELECT
T1.CId
FROM dbo.Course AS T1
INNER JOIN dbo.Teacher AS T2
ON T1.TId = T2.TId
WHERE
T2.Tname = N\'张三\'
) AS T2
ON T1.CId = T2.CId
) AS T2
ON T1.SId = T2.SId
--7.查询没有学全所有课程的同学的信息
SELECT
*
FROM
dbo.Student
WHERE SId NOT IN (
SELECT
SId
FROM
dbo.SC
GROUP BY
SId
HAVING
COUNT(DISTINCT(CId)) = (SELECT COUNT(TId) FROM dbo.Course)
)
--8.查询至少有一门课与学号为" 01 "的同学所学相同的同学的信息
SELECT
T1.*
FROM
dbo.Student AS T1
INNER JOIN (
SELECT
DISTINCT SId
FROM
dbo.SC
WHERE
CID IN (SELECT CId FROM dbo.SC WHERE SId = N\'01\')
AND SID <> N\'01\'
)AS T2
ON T1.SId = T2.SId
--9.查询和" 01 "号的同学学习的课程 完全相同的其他同学的信息
;WITH tbl_Count AS (
SELECT
SId,CId
FROM
dbo.SC
WHERE
SId IN (
SELECT
SId
FROM
dbo.SC
WHERE SId <> N\'01\'
GROUP BY SId
HAVING COUNT(DISTINCT CId) = (SELECT COUNT(DISTINCT CId) FROM dbo.SC WHERE SId = N\'01\')
)
)
SELECT
*
FROM
dbo.Student
WHERE SId IN (
SELECT
T1.SId
FROM tbl_Count AS T1
INNER JOIN (SELECT DISTINCT CId FROM dbo.SC WHERE SId = N\'01\') AS T2
ON T1.CId = T2.CId
GROUP BY T1.SId
HAVING COUNT(*) = (SELECT COUNT(DISTINCT CId) FROM dbo.SC WHERE SId = N\'01\')
)
--10.查询没学过"张三"老师讲授的任一门课程的学生姓名
SELECT
*
FROM
dbo.Student
WHERE SId NOT IN (
SELECT
T1.SId
FROM
dbo.SC AS T1
INNER JOIN (
SELECT
T1.CId
FROM dbo.Course AS T1
INNER JOIN dbo.Teacher AS T2
ON T1.TId = T2.TId
WHERE
T2.Tname = N\'张三\'
) AS T2
ON T1.CId = T2.CId
)
--11.查询两门及其以上不及格课程的同学的学号，姓名及其平均成绩
SELECT
SId
,AVG(score) AS N\'平均成绩\'
FROM
dbo.SC
WHERE
score < 60
GROUP BY SId
HAVING COUNT(*) >=2
--12.检索" 01 "课程分数小于 60，按分数降序排列的学生信息
SELECT
T1.*
,T2.score
FROM
dbo.Student AS T1
INNER JOIN dbo.SC AS T2
ON T1.SId = T2.SId
AND T2.CId = N\'01\'
AND T2.score <60
ORDER BY T2.score DESC
--13.按平均成绩从高到低显示所有学生的所有课程的成绩以及平均成绩
;WITH tbl_avgCourse AS (
SELECT
T1.SId
,T1.Sname
,AVG(T2.score) AS N\'平均成绩\'
FROM
dbo.Student AS T1
LEFT OUTER JOIN dbo.SC AS T2
ON T1.SId = T2.SId
GROUP BY
T1.SId
,T1.Sname
)
SELECT
T1.SId
,T1.Sname
,T2.CId
,T2.score
,T1.[平均成绩]
FROM
tbl_avgCourse AS T1
LEFT OUTER JOIN dbo.SC AS T2
ON T1.SId = T2.SId
ORDER BY T1.平均成绩 DESC
/*
14.查询各科成绩最高分、最低分和平均分：
以如下形式显示：课程 ID，课程 name，最高分，最低分，平均分，及格率，中等率，优良率，优秀率
及格为>=60，中等为：70-80，优良为：80-90，优秀为：>=90
要求输出课程号和选修人数，查询结果按人数降序排列，若人数相同，按课程号升序排列*/
;WITH tbl_Main AS (
SELECT
CId
,MAX(score) AS N\'最高分\'
,MIN(score) AS N\'最低分\'
,AVG(score) AS N\'平均分\'
,COUNT(*) AS N\'选课人数\'
FROM
dbo.SC
GROUP BY CId
)
,tbl_Detail AS (
SELECT
CId
,SUM(CASE WHEN score >=60 AND score <70THEN 1 ELSE 0 END) AS N\'及格\'
,SUM(CASE WHEN score >=70 AND score <80 THEN 1 ELSE 0 END) AS N\'中等\'
,SUM(CASE WHEN score >=80 AND score <90 THEN 1 ELSE 0 END) AS N\'优良\'
,SUM(CASE WHEN score >=90 THEN 1 ELSE 0 END) AS N\'优秀\'
FROM dbo.SC
GROUP BY CId
)
SELECT
T1.CId
,T2.Cname
,T1.选课人数
,T1.最高分
,T1.最低分
,T1.平均分
,[及格率] = CONVERT(NUMERIC(5,1),T3.及格) / CONVERT(NUMERIC(5,1),T1.选课人数)
,[中等率] = T3.中等 / CONVERT(NUMERIC(5,1),T1.选课人数)
,[优良率] = T3.优良 / CONVERT(NUMERIC(5,1),T1.选课人数)
,[优秀率] = T3.优秀 / CONVERT(NUMERIC(5,1),T1.选课人数)
FROM
tbl_Main AS T1
LEFT OUTER JOIN dbo.Course AS T2
ON T1.CId = T2.CId
LEFT OUTER JOIN tbl_Detail AS T3
ON T3.CId = T1.CId
ORDER BY t1.选课人数 DESC , t1.CId ASC
--15.按各科成绩进行排序，并显示排名， Score 重复时保留名次空缺
SELECT
*
,RANK() OVER (PARTITION BY Sid ORDER BY score ASC ) AS N\'排序\'
FROM
dbo.SC
ORDER BY sid ASC,score ASC
--15.1 按各科成绩进行排序，并显示排名， Score 重复时合并名次
SELECT
*
,ROW_NUMBER() OVER (PARTITION BY Sid ORDER BY score ASC ) AS N\'排序\'
FROM
dbo.SC
ORDER BY sid ASC,score ASC
--16.查询学生的总成绩，并进行排名，总分重复时保留名次空缺
SELECT
SId
,SUM(score) 总成绩
,RANK() OVER(ORDER BY SUM(score)) AS N\'排名\'
FROM
dbo.SC
GROUP BY SId
--16.1 查询学生的总成绩，并进行排名，总分重复时不保留名次空缺
SELECT
SId
,SUM(score) 总成绩
,ROW_NUMBER() OVER(ORDER BY SUM(score)) AS N\'排名\'
FROM
dbo.SC
GROUP BY SId
--17.统计各科成绩各分数段人数：课程编号，课程名称，[100-85]，[85-70]，[70-60]，[60-0] 及所占百分比
SELECT
T1.CId
,COUNT(*) AS N\'选课人数\'
,T2.Cname
,CAST(CAST(SUM(CASE WHEN T1.score <=60 THEN 1 ELSE 0 END) / CONVERT(NUMERIC(5,1),COUNT(*))*100 as numeric(3,0)) as varchar(10)) +\'%\' AS N\'[60-0]所占百分比\'
,CAST(CAST(SUM(CASE WHEN T1.score <=70 AND T1.score >60 THEN 1 ELSE 0 END) / CONVERT(NUMERIC(5,1),COUNT(*))*100 as numeric(3,0)) as varchar(10)) +\'%\' AS N\'[70-60]所占百分比\'
,CAST(CAST(SUM(CASE WHEN T1.score <=85 AND T1.score >70 THEN 1 ELSE 0 END) / CONVERT(NUMERIC(5,1),COUNT(*))*100 as numeric(3,0)) as varchar(10)) +\'%\' AS N\'[85-70]所占百分比\'
,CAST(CAST(SUM(CASE WHEN T1.score <=100 AND T1.score >85 THEN 1 ELSE 0 END) / CONVERT(NUMERIC(5,1),COUNT(*))*100 as numeric(3,0)) as varchar(10)) +\'%\' AS N\'[100-85]所占百分比\'
FROM
dbo.SC T1
LEFT OUTER JOIN dbo.Course T2
ON T1.CId = T2.CId
GROUP BY
T1.CId
,T2.Cname
--18.查询各科成绩前三名的记录
SELECT
T1.CId
,T1.score
FROM
(
SELECT
CId
,score
,ROW_NUMBER() OVER(PARTITION BY cid ORDER BY score DESC) AS N\'OrderKey\'
FROM
dbo.SC
) AS T1
WHERE
T1.OrderKey <= 3
--19.查询每门课程被选修的学生数
SELECT
T1.CId
,COUNT(T2.score) AS N\'选课人数\'
FROM
dbo.Course AS T1
INNER JOIN dbo.SC AS T2
ON T1.CId = T2.CId
GROUP BY
T1.CId
--20.查询出只选修两门课程的学生学号和姓名
SELECT
T2.SId
,T1.Sname
FROM
dbo.Student AS T1
INNER JOIN dbo.SC AS T2
ON T1.SId = T2.SId
GROUP BY T2.SId,T1.Sname
HAVING COUNT(*) = 2
--21.查询男生、女生人数
SELECT
Ssex
,COUNT(*) AS \'人数\'
FROM
dbo.Student
GROUP BY Ssex
--22.查询名字中含有「风」字的学生信息
SELECT
*
FROM
dbo.Student
WHERE
Sname LIKE N\'%风%\'
--23.查询同名同性学生名单，并统计同名人数
SELECT
Sname
,COUNT(*) AS N\'同名人数\'
FROM
dbo.Student
GROUP BY
Sname
HAVING COUNT(*) >1
--24.查询 1990 年出生的学生名单
SELECT
*
FROM
dbo.Student
WHERE
Sage > N\'1989-12-31 00:00:00.000\'
AND Sage < N\'1991-01-01 00:00:00.000\'
--25.查询每门课程的平均成绩，结果按平均成绩降序排列，平均成绩相同时，按课程编号升序排列
SELECT
CId
,AVG(score) AS N\'平均成绩\'
FROM
dbo.SC
GROUP BY CId
ORDER BY 平均成绩 DESC ,CId ASC
--26.查询平均成绩大于等于 85 的所有学生的学号、姓名和平均成绩
SELECT
T2.SId
,T1.Sname
,AVG(T2.score) AS N\'平均成绩\'
FROM
dbo.Student AS T1
INNER JOIN dbo.SC AS T2
ON T1.SId = T2.SId
GROUP BY T2.SId,T1.Sname
HAVING AVG(T2.score) >= 85
--27.查询课程名称为「数学」，且分数低于 60 的学生姓名和分数
SELECT
T1.Sname
,t2.score
FROM
dbo.Student AS T1
LEFT OUTER JOIN dbo.SC AS T2
ON T1.SId = T2.CId
LEFT OUTER JOIN dbo.Course AS T3
ON T3.CId = T2.CId
WHERE
T3.Cname =N\'数学\'
AND T2.score <60
--28.查询所有学生的课程及分数情况（存在学生没成绩，没选课的情况）
SELECT
T1.SId
,T2.CId
,T2.score
FROM
dbo.Student AS T1
LEFT OUTER JOIN dbo.SC AS T2
ON T1.SId = T2.SId
--29.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
;WITH tbl_SId AS (
SELECT
SId
,COUNT(*) AS N\'选课数\'
FROM
dbo.SC
GROUP BY SId
INTERSECT
SELECT
SId
,COUNT(*) AS N\'成绩大于70的课程数\'
FROM
dbo.SC
WHERE score > 70
GROUP BY SId
)
SELECT
T1.Sname
,T3.Cname
,T2.score
FROM
dbo.Student AS T1
INNER JOIN dbo.SC AS T2
ON T1.SId = T2.SId
INNER JOIN dbo.Course AS T3
ON T2.CId = T3.CId
INNER JOIN tbl_SId AS T4
ON T1.SId = T4.SId
--30.查询不及格的课程
SELECT
*
FROM
dbo.SC
WHERE
score <60
--31.查询课程编号为 01 且课程成绩在 80 分以上的学生的学号和姓名
SELECT
T1.SId
,T1.Sname
FROM
dbo.Student AS T1
INNER JOIN dbo.SC AS T2
ON T1.SId = T2.SId
WHERE
T2.score >80
AND T2.CId = N\'01\'
--32.求每门课程的学生人数
SELECT
T1.CId
,COUNT(T2.score) AS N\'选课人数\'
FROM
dbo.Course AS T1
INNER JOIN dbo.SC AS T2
ON T1.CId = T2.CId
GROUP BY
T1.CId
--33.成绩不重复，查询选修「张三」老师所授课程的学生中，成绩最高的学生信息及其成绩
SELECT
TOP 1 T1.*,T2.score
FROM
dbo.Student AS T1
INNER JOIN dbo.SC AS T2
ON T1.SId = T2.SId
LEFT OUTER JOIN dbo.Teacher AS T3
ON T2.CId = T3.TId
WHERE
T3.Tname = N\'张三\'
ORDER BY T2.score DESC
--34.成绩有重复的情况下，查询选修「张三」老师所授课程的学生中，成绩最高的学生信息及其成绩
SELECT
TOP 1 WITH TIES T1.*,T2.score
FROM
dbo.Student AS T1
INNER JOIN dbo.SC AS T2
ON T1.SId = T2.SId
LEFT OUTER JOIN dbo.Teacher AS T3
ON T2.CId = T3.TId
WHERE
T3.Tname = N\'张三\'
ORDER BY T2.score DESC
--35.查询不同课程成绩相同的学生的学生编号、课程编号、学生成绩
;WITH tbl_Data AS (
SELECT
T1.SId
,T2.score
FROM
dbo.Student AS T1
INNER JOIN dbo.SC AS T2
ON T1.SId = T2.SId
GROUP BY T1.SId,T2.score
HAVING COUNT(*) >=2
)
SELECT
T2.SId
,T1.CId
,T2.score
FROM
dbo.SC AS T1
INNER JOIN tbl_Data AS T2
ON T1.SId = T2.SId
AND T1.score = T2.score
--36.查询每门功成绩最好的前两名
SELECT
T1.*
FROM (
SELECT
*
,ROW_NUMBER() OVER (PARTITION BY CId ORDER BY score DESC) AS N\'SortKey\'
FROM
dbo.SC
) AS T1
WHERE
T1.SortKey <= 2
--37.统计每门课程的学生选修人数（超过 5 人的课程才统计）。
SELECT
CId
FROM
dbo.SC
GROUP BY CId
HAVING COUNT(*) >= 5
--38.检索至少选修两门课程的学生学号
SELECT
SId
FROM
dbo.SC
GROUP BY SId
HAVING COUNT(*) >1
--39.查询选修了全部课程的学生信息
SELECT
SId
FROM
dbo.SC
GROUP BY SId
HAVING COUNT(*) = (SELECT COUNT(DISTINCT CId) FROM dbo.Course)
--40.查询各学生的年龄，只按年份来算
SELECT
*
,N\'年龄\' = YEAR(GETDATE()) - YEAR(Sage)
FROM
dbo.Student
--41.按照出生日期来算，当前月日 < 出生年月的月日则，年龄减一
SELECT
*
,N\'年龄\' = IIF(RIGHT(CONVERT(NVARCHAR(20),GETDATE(),112),4) < RIGHT(CONVERT(NVARCHAR(20),Sage,112),4) ,YEAR(GETDATE()) - YEAR(Sage) - 1,YEAR(GETDATE()) - YEAR(Sage))
FROM
dbo.Student
--42.查询本周过生日的学生
DECLARE @CurrentWeekFirst AS DATETIME,
@NextWeekFirst AS DATETIME
SELECT @CurrentWeekFirst = DATEADD(WEEK, DATEDIFF(WEEK, 0, GETDATE()), 0),
@NextWeekFirst = DATEADD(WEEK, DATEDIFF(WEEK, 0, GETDATE())+1, 0)
SELECT
*
FROM
dbo.Student
WHERE
DATEADD(Year,DATEDIFF(Year,Sage,@CurrentWeekFirst),Sage)
BETWEEN @CurrentWeekFirst AND @NextWeekFirst
--43.查询下周过生日的学生
DECLARE @CurrentWeekFirst AS DATETIME,
@NextWeekFirst AS DATETIME
SELECT @CurrentWeekFirst = DATEADD(WEEK, DATEDIFF(WEEK, 0, GETDATE())+1, 0),
@NextWeekFirst = DATEADD(WEEK, DATEDIFF(WEEK, 0, GETDATE())+2, 0)
SELECT
*
FROM
dbo.Student
WHERE
DATEADD(Year,DATEDIFF(Year,Sage,@CurrentWeekFirst),Sage)
BETWEEN @CurrentWeekFirst AND @NextWeekFirst
OR DATEADD(Year,DATEDIFF(Year,Sage,@NextWeekFirst),Sage)
BETWEEN @CurrentWeekFirst AND @NextWeekFirst
--44.查询本月过生日的学生
SELECT
*
FROM
dbo.Student
WHERE
MONTH(GETDATE()) = MONTH(Sage)
--45.查询下月过生日的学生
SELECT
*
FROM
dbo.Student
WHERE
MONTH(GETDATE()) +1 = MONTH(Sage)