1. 程式人生 > >50個常用的SQL語句

50個常用的SQL語句

Code:

    50個常用SQL語句              Student(S#,Sname,Sage,Ssex) 學生表  S#學號,主鍵       Course(C#,Cname,T#) 課程表          C#課程號,主鍵       SC(S#,C#,score) 成績表       Teacher(T#,Tname) 教師表            T#教師編號,主鍵              問題:       1、查詢“001”課程比“002”課程成績高的所有學生的學號;       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、查詢平均成績大於60分的同學的學號和平均成績;       select S#,avg(score)       from sc       group by S# having avg(score) >60;       3、查詢所有同學的學號、姓名、選課數、總成績;       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”的老師的個數;       select count(distinct(Tname))       from 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 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、查詢學過“001”並且也學過編號“002”課程的同學的學號、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、查詢學過“葉平”老師所教的所有課的同學的學號、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“002”的成績比課程編號“001”課程低的所有同學的學號、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、查詢所有課程成績小於60分的同學的學號、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、查詢沒有學全所有課的同學的學號、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號為“1001”的同學所學相同的同學的學號和姓名;       select S#,Sname from Student,SC where Student.S#=SC.S# and C# in select C# from SC where S#='1001';       12、查詢至少學過學號為“001”同學所有一門課的其他同學學號和姓名;       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”老師教的課的成績都更改為此課程的平均成績;       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”號的同學學習的課程完全相同的其他同學學號和姓名;       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、刪除學習“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“003”課程的同學學號、2、       號課的平均成績;       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、按平均成績從高到低顯示所有學生的“資料庫”、“企業管理”、“英語”三門的課程成績,按如下形式顯示: 學生ID,,資料庫,企業管理,英語,有效課程數,有效平均分       SELECT S# as 學生ID       ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='004') AS 資料庫       ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='001') AS 企業管理       ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='006') AS 英語       ,COUNT(*) AS 有效課程數, AVG(t.score) AS 平均成績       FROM SC AS t       GROUP BY S#       ORDER BY avg(t.score)       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 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、按各科平均成績從低到高和及格率的百分數從高到低順序       SELECT t.C# AS 課程號,max(course.Cname)AS 課程名,isnull(AVG(score),0) AS 平均成績       ,100 * SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) AS 及格百分數       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),馬哲(002),OO&UML (003),資料庫(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 企業管理及格百分數       ,SUM(CASE WHEN C# = '002' THEN score ELSE 0 END)/SUM(CASE C# WHEN '002' THEN 1 ELSE 0 END) AS 馬哲平均分       ,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 馬哲及格百分數       ,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及格百分數       ,SUM(CASE WHEN C# = '004' THEN score ELSE 0 END)/SUM(CASE C# WHEN '004' THEN 1 ELSE 0 END) AS 資料庫平均分       ,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 資料庫及格百分數       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       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),馬哲(002),UML (003),資料庫(004)       [學生ID],[學生姓名],企業管理,馬哲,UML,資料庫,平均成績       SELECT DISTINCT top 3       SC.S# As 學生學號,       Student.Sname AS 學生姓名 ,       T1.score AS 企業管理,       T2.score AS 馬哲,       T3.score AS UML,       T4.score AS 資料庫,       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 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、查詢學生平均成績及其名次       SELECT 1+(SELECT COUNT( distinct 平均成績)       FROM (SELECT S#,AVG(score) AS 平均成績       FROM SC       GROUP BY S#       ) AS T1       WHERE 平均成績 > T2.平均成績) as 名次,       S# as 學生學號,平均成績       FROM (SELECT S#,AVG(score) 平均成績       FROM SC       GROUP BY S#       ) AS T2       ORDER BY 平均成績 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.S# as 學生ID,t1.C# as 課程ID,Score as 分數       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生數       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生的學號和姓名       select SC.S#,Student.Sname,count(C#) AS 選課數       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       Select count(Ssex) as 男生人數 from Student group by Ssex having Ssex='男';       Select count(Ssex) as 女生人數 from Student group by Ssex having Ssex='女';       29、查詢姓“張”的學生名單       SELECT Sname FROM 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 Student group by Sname having count(*)>1;;       31、1981年出生的學生名單(注:Student表中Sage列的型別是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,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 C#,Avg(score) from SC group by C# order by Avg(score),C# 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 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“資料庫”,且分數低於60的學生姓名和分數       Select Sname,isnull(score,0)       from Student,SC,Course       where SC.S#=Student.S# and SC.C#=Course.C# and Course.Cname='資料庫'and score <60;       35、查詢所有學生的選課情況;       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 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,並按課程號從大到小排列       select c# from sc where scor e <60 order by C# ;       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 SC.S#,Student.Sname from SC,Student where SC.S#=Student.S# and Score>80 and C#='003';       39、求選了課程的學生人數       select count(*) from sc;       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 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、查詢各個課程及相應的選修人數       select count(*) from sc group by C#;       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 A.S#,B.score from SC A ,SC B where A.Score=B.Score and A.C# <>B.C# ;       43、查詢每門功成績最好的前兩名       SELECT t1.S# as 學生ID,t1.C# as 課程ID,Score as 分數       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 C# as 課程號,count(*) as 人數       from sc       group by C#       order by count(*) desc,c#       45、檢索至少選修兩門課程的學生學號       select S#       from sc       group by s#       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 C#,Cname       from Course       where C# in (select c# from sc group by c#)       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 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的學號及其平均成績       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”課程分數小於60,按分數降序排列的同學學號       select S# from SC where C#='004'and score <60 order by score desc;       50、刪除“002”同學的“001”課程的成績       delete from Sc where S#='001'and C#='001';