sql50条常用语句(以学生表为例)

1、50条常用语句（以学生表为例）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“”课程比“”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 &

2、#160; WHERE a.score>b.score AND a.s#=b.s#;  2、查询平均成绩大于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#),s

3、um(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；    SELECT Student.S#

4、,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“”并且也学过编号“”课程的同学的学号、姓名；  SELECT Student.S#,Student.S

5、name 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 ,Cours

6、e ,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“”的成绩比课程编号“”课程低的所有同学的学号、姓名；  SELECT S#,Sname FROM (SELECT Student

7、.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分的同学的学号、姓名；  SELECT S#,Sname   FROM Student  

8、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 co

9、unt(C#) <(SELECT count(C#) FROM Course); 11、查询至少有一门课与学号为“”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“”同学所有一门课的其他同学学号和姓名；    SELECT distinct SC.S#,Sname &#

10、160;   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     WH

11、ERE 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“”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(*

12、)=(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“”课程的同学

13、学号、    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

14、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   &

15、#160;    ,(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)  1

16、8、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)     

17、60;                 FROM SC AS IL,Student AS IM                       WHERE L.C# = IL.C# AND IM.S#=IL.S# 

18、                      GROUP BY IL.C#)         AND         R.Score = (SELECT MIN(IR.score)    &#

19、160;                  FROM SC AS IR                       WHERE R.C# = IR.C#     

20、;              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.

21、Cname)AS 课程名,isnull(AVG(score),0) AS 平均成绩        ,100 * SUM(CASE WHEN  isnull(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#  

22、   ORDER BY 100 * SUM(CASE WHEN  isnull(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（），马克思（），OO&UML （），数据库（）    SELECT SUM(CASE WHEN C# ='001' THEN score ELSE 0 END)/SUM(CASE C# WHEN '001' THEN

23、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 ELS

24、E 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(

25、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 

26、;       ,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# = '0

27、04' 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,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#

28、0;  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（），马克思（），UML （），数据库（）    学生ID,学生姓名,企业管理,马克思,UML,数据库,平均成绩    SELECT  DISTINCT top 3       SC.S# As 学生学号,      

29、   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

30、,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.

31、C# = '001'             LEFT JOIN SC AS T2                       ON SC.S# = T2.S# AND T2.C# = '002'  

32、0;          LEFT JOIN SC AS T3                       ON SC.S# = T3.S# AND T3.C# = '003'        &#

33、160;    LEFT JOIN SC AS T4                       ON SC.S# = T4.S# AND T4.C# = '004'       WHERE student.S#=SC.S# AND   

34、60;   ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)       NOT IN       (SELECT             DISTINCT      

35、;       TOP 15 WITH TIES             ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)       FROM sc        

36、     LEFT JOIN sc AS T1                       ON sc.S# = T1.S# AND T1.C# = 'k1'             LEFT JOIN

37、sc AS T2                       ON sc.S# = T2.S# AND T2.C# = 'k2'             LEFT JOIN sc AS T3    

38、60;                  ON sc.S# = T3.S# AND T3.C# = 'k3'             LEFT JOIN sc AS T4          &#

39、160;            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,

40、 <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

41、60;        ,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,Course     WHERE SC.C#=Course

42、.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       

43、               FROM SC                   GROUP BY S#              

44、0;    ) 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           

45、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   

46、   FROM SC t1       WHERE score IN (SELECT TOP 3 score               FROM SC               WHERE t1.C#= C#  &#

47、160;          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

48、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'  &

49、#160;  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 Student GROUP BY Sname having  count(*)>1; 31、年出生

50、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     WHERE  CONVERT(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&#

51、160;   SELECT C#,Avg(score) FROM SC GROUP BY C# ORDER BY Avg(score),C# DESC ; 33、查询平均成绩大于的所有学生的学号、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 having  

52、0; avg(score)>85; 34、查询课程名称为“数据库”，且分数低于的学生姓名和分数    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； 

53、60;  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分以上的姓名、课程名称和分数；    SELECT  distinct student.S#,student.Sname,SC.C#,SC.score     FROM

54、 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、查询课程编号为且课程成绩在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# AN

55、D 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

56、# 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       FRO