久久久久无码精品,四川省少妇一级毛片,老老熟妇xxxxhd,人妻无码少妇一区二区

數(shù)據(jù)庫常用sql語句有哪些

時(shí)間:2020-09-29 12:51:12 SQL 我要投稿

數(shù)據(jù)庫常用sql語句有哪些

  SQL語句有哪些?SQL語句無論是種類還是數(shù)量都是繁多的,很多語句也是經(jīng)常要用到的,下文yjbys小編為大家分享的就是SQL的常用語句,僅供參考!

  50個(gè)常用的sql語句

  Student(S#,Sname,Sage,Ssex) 學(xué)生表

  Course(C#,Cname,T#) 課程表

  SC(S#,C#,score) 成績(jī)表

  Teacher(T#,Tname) 教師表

  問題:

  1、查詢“001”課程比“002”課程成績(jī)高的所有學(xué)生的學(xué)號(hào);

  select a.S# from (select s#,score from SC where C#='001') a,(select s#,score

  from SC where C#='002') b

  where a.score>b.score and a.s#=b.s#;

  2、查詢平均成績(jī)大于60分的同學(xué)的學(xué)號(hào)和平均成績(jī);

  select S#,avg(score)

  from sc

  group by S# having avg(score) >60;

  3、查詢所有同學(xué)的學(xué)號(hào)、姓名、選課數(shù)、總成績(jī);

  select Student.S#,Student.Sname,count(SC.C#),sum(score)

  from Student left Outer join SC on Student.S#=SC.S#

  group by Student.S#,Sname

  4、查詢姓“李”的老師的個(gè)數(shù);

  select count(distinct(Tname))

  from Teacher

  where Tname like '李%';

  5、查詢沒學(xué)過“葉平”老師課的同學(xué)的學(xué)號(hào)、姓名;

  select Student.S#,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='葉平');

  6、查詢學(xué)過“001”并且也學(xué)過編號(hào)“002”課程的同學(xué)的學(xué)號(hào)、姓名;

  select Student.S#,Student.Sname 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、查詢學(xué)過“葉平”老師所教的所有課的同學(xué)的學(xué)號(hào)、姓名;

  select S#,Sname

  from Student

  where S# in (select S# from SC ,Course ,Teacher where SC.C#=Course.C# and Teacher.T#=Course.T# and Teacher.Tname='葉平' group by S# having count(SC.C#)=(select count(C#) from Course,Teacher where Teacher.T#=Course.T# and Tname='葉平'));

  8、查詢課程編號(hào)“002”的成績(jī)比課程編號(hào)“001”課程低的所有同學(xué)的學(xué)號(hào)、姓名;

  Select S#,Sname from (select Student.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、查詢所有課程成績(jī)小于60分的同學(xué)的學(xué)號(hào)、姓名;

  select S#,Sname

  from Student

  where S# not in (select Student.S# from Student,SC where S.S#=SC.S# and score>60);

  10、查詢沒有學(xué)全所有課的同學(xué)的學(xué)號(hào)、姓名;

  select Student.S#,Student.Sname

  from Student,SC

  where Student.S#=SC.S# group by Student.S#,Student.Sname having count(C#) <(select count(C#) from Course);

  11、查詢至少有一門課與學(xué)號(hào)為“1001”的同學(xué)所學(xué)相同的同學(xué)的學(xué)號(hào)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、查詢至少學(xué)過學(xué)號(hào)為“001”同學(xué)所有一門課的其他同學(xué)學(xué)號(hào)和姓名;

  select distinct SC.S#,Sname

  from Student,SC

  where Student.S#=SC.S# and C# in (select C# from SC where S#='001');

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

  update SC set score=(select avg(SC_2.score)

  from SC SC_2

  where SC_2.C#=SC.C# ) from Course,Teacher where Course.C#=SC.C# and Course.T#=Teacher.T# and Teacher.Tname='葉平');

  14、查詢和“1002”號(hào)的同學(xué)學(xué)習(xí)的課程完全相同的其他同學(xué)學(xué)號(hào)和姓名;

  select S# from SC where C# in (select C# from SC where S#='1002')

  group by S# having count(*)=(select count(*) from SC where S#='1002');

  15、刪除學(xué)習(xí)“葉平”老師課的SC表記錄;

  Delect SC

  from course ,Teacher

  where Course.C#=SC.C# and Course.T#= Teacher.T# and Tname='葉平';

  16、向SC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(hào)“003”課程的同學(xué)學(xué)號(hào)、2、

  號(hào)課的平均成績(jī);

  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、按平均成績(jī)從高到低顯示所有學(xué)生的“數(shù)據(jù)庫”、“企業(yè)管理”、“英語”三門的課程成績(jī),按如下形式顯示: 學(xué)生ID,,數(shù)據(jù)庫,企業(yè)管理,英語,有效課程數(shù),有效平均分

  SELECT S# as 學(xué)生ID

  ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='004') AS 數(shù)據(jù)庫

  ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='001') AS 企業(yè)管理

  ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='006') AS 英語

  ,COUNT(*) AS 有效課程數(shù), AVG(t.score) AS 平均成績(jī)

  FROM SC AS t

  GROUP BY S#

  ORDER BY avg(t.score)

  18、查詢各科成績(jī)最高和最低的分:以如下形式顯示:課程ID,最高分,最低分

  SELECT L.C# As 課程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)

  FROM SC AS IL,Student AS IM

  WHERE L.C# = IL.C# and IM.S#=IL.S#

  GROUP BY IL.C#)

  AND

  R.Score = (SELECT MIN(IR.score)

  FROM SC AS IR

  WHERE R.C# = IR.C#

  GROUP BY IR.C#

  );

  19、按各科平均成績(jī)從低到高和及格率的百分?jǐn)?shù)從高到低順序

  SELECT t.C# AS 課程號(hào),max(course.Cname)AS 課程名,isnull(AVG(score),0) AS 平均成績(jī)

  ,100 * SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) AS 及格百分?jǐn)?shù)

  FROM SC T,Course

  where t.C#=course.C#

  GROUP BY t.C#

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

  20、查詢?nèi)缦抡n程平均成績(jī)和及格率的百分?jǐn)?shù)(用"1行"顯示): 企業(yè)管理(001),馬克思(002),OO&UML (003),數(shù)據(jù)庫(004)

  SELECT SUM(CASE WHEN C# ='001' THEN score ELSE 0 END)/SUM(CASE C# WHEN '001' THEN 1 ELSE 0 END) AS 企業(yè)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 企業(yè)管理及格百分?jǐn)?shù)

  ,SUM(CASE WHEN C# = '002' THEN score ELSE 0 END)/SUM(CASE C# WHEN '002' THEN 1 ELSE 0 END) AS 馬克思平均分

  ,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 馬克思及格百分?jǐn)?shù)

  ,SUM(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?jǐn)?shù)

  ,SUM(CASE WHEN C# = '004' THEN score ELSE 0 END)/SUM(CASE C# WHEN '004' THEN 1 ELSE 0 END) AS 數(shù)據(jù)庫平均分

  ,100 * SUM(CASE WHEN C# = '004' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '004' THEN 1 ELSE 0 END) AS 數(shù)據(jù)庫及格百分?jǐn)?shù)

  FROM SC

  21、查詢不同老師所教不同課程平均分從高到低顯示

  SELECT max(Z.T#) AS 教師ID,MAX(Z.Tname) AS 教師姓名,C.C# AS 課程ID,MAX(C.Cname) AS 課程名稱,AVG(Score) AS 平均成績(jī)

  FROM SC AS T,Course AS C ,Teacher AS Z

  where T.C#=C.C# and C.T#=Z.T#

  GROUP BY C.C#

  ORDER BY AVG(Score) DESC

  22、查詢?nèi)缦抡n程成績(jī)第 3 名到第 6 名的學(xué)生成績(jī)單:企業(yè)管理(001),馬克思(002),UML (003),數(shù)據(jù)庫(004)

  [學(xué)生ID],[學(xué)生姓名],企業(yè)管理,馬克思,UML,數(shù)據(jù)庫,平均成績(jī)

  SELECT DISTINCT top 3

  SC.S# As 學(xué)生學(xué)號(hào),

  Student.Sname AS 學(xué)生姓名 ,

  T1.score AS 企業(yè)管理,

  T2.score AS 馬克思,

  T3.score AS UML,

  T4.score AS 數(shù)據(jù)庫,

  ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) as 總分

  FROM Student,SC LEFT JOIN SC AS T1

  ON SC.S# = T1.S# AND T1.C# = '001'

  LEFT JOIN SC AS T2

  ON SC.S# = T2.S# AND T2.C# = '002'

  LEFT JOIN SC AS T3

  ON SC.S# = T3.S# AND T3.C# = '003'

  LEFT JOIN SC AS T4

  ON SC.S# = T4.S# AND T4.C# = '004'

  WHERE student.S#=SC.S# and

  ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)

  NOT IN

  (SELECT

  DISTINCT

  TOP 15 WITH TIES

  ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)

  FROM sc

  LEFT JOIN sc AS T1

  ON sc.S# = T1.S# AND T1.C# = 'k1'

  LEFT JOIN sc AS T2

  ON sc.S# = T2.S# AND T2.C# = 'k2'

  LEFT JOIN sc AS T3

  ON sc.S# = T3.S# AND T3.C# = 'k3'

  LEFT JOIN sc AS T4

  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、統(tǒng)計(jì)列印各科成績(jī),各分?jǐn)?shù)段人數(shù):課程ID,課程名稱,[100-85],[85-70],[70-60],[ <60]

  SELECT SC.C# as 課程ID, Cname as 課程名稱

  ,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]

  ,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.C#

  GROUP BY SC.C#,Cname;

  24、查詢學(xué)生平均成績(jī)及其名次

  SELECT 1+(SELECT COUNT( distinct 平均成績(jī))

  FROM (SELECT S#,AVG(score) AS 平均成績(jī)

  FROM SC

  GROUP BY S#

  ) AS T1

  WHERE 平均成績(jī) > T2.平均成績(jī)) as 名次,

  S# as 學(xué)生學(xué)號(hào),平均成績(jī)

  FROM (SELECT S#,AVG(score) 平均成績(jī)

  FROM SC

  GROUP BY S#

  ) AS T2

  ORDER BY 平均成績(jī) desc;

  25、查詢各科成績(jī)前三名的記錄:(不考慮成績(jī)并列情況)

  SELECT t1.S# as 學(xué)生ID,t1.C# as 課程ID,Score as 分?jǐn)?shù)

  FROM SC t1

  WHERE score IN (SELECT TOP 3 score

  FROM SC

  WHERE t1.C#= C#

  ORDER BY score DESC

  )

  ORDER BY t1.C#;

  26、查詢每門課程被選修的學(xué)生數(shù)

  select c#,count(S#) from sc group by C#;

  27、查詢出只選修了一門課程的全部學(xué)生的學(xué)號(hào)和姓名

  select SC.S#,Student.Sname,count(C#) AS 選課數(shù)

  from SC ,Student

  where SC.S#=Student.S# group by SC.S# ,Student.Sname having count(C#)=1;

  28、查詢男生、女生人數(shù)

  Select count(Ssex) as 男生人數(shù) from Student group by Ssex having Ssex='男';

  Select count(Ssex) as 女生人數(shù) from Student group by Ssex having Ssex='女';

  29、查詢姓“張”的.學(xué)生名單

  SELECT Sname FROM Student WHERE Sname like '張%';

  30、查詢同名同性學(xué)生名單,并統(tǒng)計(jì)同名人數(shù)

  select Sname,count(*) from Student group by Sname having count(*)>1;;

  31、1981年出生的學(xué)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 student

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

  32、查詢每門課程的平均成績(jī),結(jié)果按平均成績(jī)升序排列,平均成績(jī)相同時(shí),按課程號(hào)降序排列

  Select C#,Avg(score) from SC group by C# order by Avg(score),C# DESC ;

  33、查詢平均成績(jī)大于85的所有學(xué)生的學(xué)號(hào)、姓名和平均成績(jī)

  select Sname,SC.S# ,avg(score)

  from Student,SC

  where Student.S#=SC.S# group by SC.S#,Sname having    avg(score)>85;

  34、查詢課程名稱為“數(shù)據(jù)庫”,且分?jǐn)?shù)低于60的學(xué)生姓名和分?jǐn)?shù)

  Select Sname,isnull(score,0)

  from Student,SC,Course

  where SC.S#=Student.S# and SC.C#=Course.C# and Course.Cname='數(shù)據(jù)庫'and score <60;

  35、查詢所有學(xué)生的選課情況;

  SELECT SC.S#,SC.C#,Sname,Cname

  FROM SC,Student,Course

  where SC.S#=Student.S# and SC.C#=Course.C# ;

  36、查詢?nèi)魏我婚T課程成績(jī)?cè)?0分以上的姓名、課程名稱和分?jǐn)?shù);

  SELECT distinct student.S#,student.Sname,SC.C#,SC.score

  FROM student,Sc

  WHERE SC.score>=70 AND SC.S#=student.S#;

  37、查詢不及格的課程,并按課程號(hào)從大到小排列

  select c# from sc where scor e <60 order by C# ;

  38、查詢課程編號(hào)為003且課程成績(jī)?cè)?0分以上的學(xué)生的學(xué)號(hào)和姓名;

  select SC.S#,Student.Sname from SC,Student where SC.S#=Student.S# and Score>80 and C#='003';

  39、求選了課程的學(xué)生人數(shù)

  select count(*) from sc;

  40、查詢選修“葉平”老師所授課程的學(xué)生中,成績(jī)最高的學(xué)生姓名及其成績(jī)

  select Student.Sname,score

  from Student,SC,Course C,Teacher

  where Student.S#=SC.S# and SC.C#=C.C# and C.T#=Teacher.T# and Teacher.Tname='葉平' and SC.score=(select max(score)from SC where C#=C.C# );

  41、查詢各個(gè)課程及相應(yīng)的選修人數(shù)

  select count(*) from sc group by C#;

  42、查詢不同課程成績(jī)相同的學(xué)生的學(xué)號(hào)、課程號(hào)、學(xué)生成績(jī)

  select distinct A.S#,B.score from SC A ,SC B where A.Score=B.Score and A.C# <>B.C# ;

  43、查詢每門功成績(jī)最好的前兩名

  SELECT t1.S# as 學(xué)生ID,t1.C# as 課程ID,Score as 分?jǐn)?shù)

  FROM SC t1

  WHERE score IN (SELECT TOP 2 score

  FROM SC

  WHERE t1.C#= C#

  ORDER BY score DESC

  )

  ORDER BY t1.C#;

  44、統(tǒng)計(jì)每門課程的學(xué)生選修人數(shù)(超過10人的課程才統(tǒng)計(jì))。要求輸出課程號(hào)和選修人數(shù),查詢結(jié)果按人數(shù)降序排列,查詢結(jié)果按人數(shù)降序排列,若人數(shù)相同,按課程號(hào)升序排列

  select C# as 課程號(hào),count(*) as 人數(shù)

  from sc

  group by C#

  order by count(*) desc,c#

  45、檢索至少選修兩門課程的學(xué)生學(xué)號(hào)

  select S#

  from sc

  group by s#

  having count(*) > = 2

  46、查詢?nèi)繉W(xué)生都選修的課程的課程號(hào)和課程名

  select C#,Cname

  from Course

  where C# in (select c# from sc group by c#)

  47、查詢沒學(xué)過“葉平”老師講授的任一門課程的學(xué)生姓名

  select Sname from Student where S# not in (select S# from Course,Teacher,SC where Course.T#=Teacher.T# and SC.C#=course.C# and Tname='葉平');

  48、查詢兩門以上不及格課程的同學(xué)的學(xué)號(hào)及其平均成績(jī)

  select S#,avg(isnull(score,0)) from SC where S# in (select S# from SC where score <60 group by S# having count(*)>2)group by S#;

  49、檢索“004”課程分?jǐn)?shù)小于60,按分?jǐn)?shù)降序排列的同學(xué)學(xué)號(hào)

  select S# from SC where C#='004'and score <60 order by score desc;

  50、刪除“002”同學(xué)的“001”課程的成績(jī)

  delete from Sc where S#='001'and C#='001';

【數(shù)據(jù)庫常用sql語句有哪些】相關(guān)文章:

50個(gè)常用的SQL語句11-12

SQL常用語句大全10-16

SQL常用增刪改查語句10-06

SQL常用增刪改查語句大全11-14

Dedecms中常用數(shù)據(jù)調(diào)用的sql語句11-12

經(jīng)典SQL語句大全11-12

sql語句相關(guān)測(cè)試11-12

SQL語句結(jié)構(gòu)示例11-12

sql語句的使用11-12