導(dǎo)讀:1建站知識(shí)這篇文字在網(wǎng)上被轉(zhuǎn)載爛了，里面有些sql適合用在應(yīng)用系統(tǒng)里，有些“報(bào)表”的感 覺(jué)更重些，主要是想復(fù)習(xí)前者網(wǎng)站優(yōu)化seo培訓(xùn)網(wǎng)站建設(shè)教程。

50個(gè)常用sql語(yǔ)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(wèn)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(méi)學(xué)過(guò)“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(guò)“001”并且也學(xué)過(guò)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(guò)“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(méi)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(mén)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(guò)學(xué)號(hào)為“001”同學(xué)所有一門(mén)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(méi)有上過(guò)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(kù)”、“企業(yè)管理”、“英語(yǔ)”三門(mén)的課程成績(jī)，按如下形式顯示： 學(xué)生ID,,數(shù)據(jù)庫(kù),企業(yè)管理,英語(yǔ),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(kù) ,(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(yǔ) ,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(kù)（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 E網(wǎng)站建設(shè)哪家好LSE 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(kù)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(kù)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(kù)（004） [學(xué)生ID],[學(xué)生姓名],企業(yè)管理,馬克思,UML,數(shù)據(jù)庫(kù),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(kù), 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(mén)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(mén)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(mén)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(kù)”，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(kù)'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(mén)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 網(wǎng)站建設(shè)多少錢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(mén)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(mén)課程的學(xué)生選修人數(shù)（超過(guò)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建設(shè)網(wǎng)站公司# 45、檢索至少選修兩門(mén)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(méi)學(xué)過(guò)“葉平”老師講授的任一門(mén)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(mén)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'; 作者 不常在相關(guān)網(wǎng)站優(yōu)化seo培訓(xùn)網(wǎng)站建設(shè)教程。

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