1. Student(S#,Sname,Sage,Ssex) 学生表
2. Course(C#,Cname,T#) 课程表
3. SC(S#,C#,score) 成绩表
4. Teacher(T#,Tname) 教师表
5.
6. 问题：
7. 1、查询“001”课程比“002”课程成绩高的所有学生的学号；
8. select a.S# from (select s#,score from SC where C#='001') a,(select s#,score
9. from SC where C#='002') b
10. where a.score>b.score and a.s#=b.s#;
11. 2、查询平均成绩大于60分的同学的学号和平均成绩；
12. select S#,avg(score)
13. from sc
14. group by S# having avg(score) >60;
15. 3、查询所有同学的学号、姓名、选课数、总成绩；
16. select Student.S#,Student.Sname,count(SC.C#),sum(score)
17. from Student left Outer join SC on Student.S#=SC.S#
18. group by Student.S#,Sname
19. 4、查询姓“李”的老师的个数；
20. select count(distinct(Tname))
21. from Teacher
22. where Tname like '李%';
23. 5、查询没学过“叶平”老师课的同学的学号、姓名；
24. select Student.S#,Student.Sname
25. from Student
26. 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');
27. 6、查询学过“001”并且也学过编号“002”课程的同学的学号、姓名；
28. 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');
29. 7、查询学过“叶平”老师所教的所有课的同学的学号、姓名；
30. select S#,Sname
31. from Student
32. where S# in (select S# from SC ,Course ,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'));
33. 8、查询课程编号“002”的成绩比课程编号“001”课程低的所有同学的学号、姓名；
34. 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
35. from Student,SC where Student.S#=SC.S# and C#='001') S_2 where score2 <score;
36. 9、查询所有课程成绩小于60分的同学的学号、姓名；
37. select S#,Sname
38. from Student
39. where S# not in (select Student.S# from Student,SC where S.S#=SC.S# and score>60);
40. 10、查询没有学全所有课的同学的学号、姓名；
41. select Student.S#,Student.Sname
42. from Student,SC
43. where Student.S#=SC.S# group by Student.S#,Student.Sname having count(C#) <(select count(C#) from Course);
44.
45. 11、查询至少有一门课与学号为“1001”的同学所学相同的同学的学号和姓名；
46. select S#,Sname from Student,SC where Student.S#=SC.S# and C# in select C# from SC where S#='1001';
47. 12、查询至少学过学号为“001”同学所有一门课的其他同学学号和姓名；
48. select distinct SC.S#,Sname
49. from Student,SC
50. where Student.S#=SC.S# and C# in (select C# from SC where S#='001');
51. 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；
52. update SC set score=(select avg(SC_2.score)
53. from SC SC_2
54. where SC_2.C#=SC.C# ) from Course,Teacher where Course.C#=SC.C# and Course.T#=Teacher.T# and Teacher.Tname='叶平');
55. 14、查询和“1002”号的同学学习的课程完全相同的其他同学学号和姓名；
56. select S# from SC where C# in (select C# from SC where S#='1002')
57. group by S# having count(*)=(select count(*) from SC where S#='1002');
58. 15、删除学习“叶平”老师课的SC表记录；
59. Delect SC
60. from course ,Teacher
61. where Course.C#=SC.C# and Course.T#= Teacher.T# and Tname='叶平';
62. 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“003”课程的同学学号、2、
63. 号课的平均成绩；
64. Insert SC select S#,'002',(Select avg(score)
65. from SC where C#='002') from Student where S# not in (Select S# from SC where C#='002');
66. 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,企业管理,英语,有效课程数,有效平均分
67. SELECT S# as 学生ID
68. ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='004') AS 数据库
69. ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='001') AS 企业管理
70. ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='006') AS 英语
71. ,COUNT(*) AS 有效课程数, AVG(t.score) AS 平均成绩
72. FROM SC AS t
73. GROUP BY S#
74. ORDER BY avg(t.score)
75. 18、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
76. SELECT L.C# As 课程ID,L.score AS 最高分,R.score AS 最低分
77. FROM SC L ,SC AS R
78. WHERE L.C# = R.C# and
79. L.score = (SELECT MAX(IL.score)
80. FROM SC AS IL,Student AS IM
81. WHERE L.C# = IL.C# and IM.S#=IL.S#
82. GROUP BY IL.C#)
83. AND
84. R.Score = (SELECT MIN(IR.score)
85. FROM SC AS IR
86. WHERE R.C# = IR.C#
87. GROUP BY IR.C#
88. );
89. 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
90. SELECT t.C# AS 课程号,max(course.Cname)AS 课程名,isnull(AVG(score),0) AS 平均成绩
91. ,100 * SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) AS 及格百分数
92. FROM SC T,Course
93. where t.C#=course.C#
94. GROUP BY t.C#
95. ORDER BY 100 * SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) DESC
96. 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（001），马克思（002），OO&UML （003），数据库（004）
97. SELECT SUM(CASE WHEN C# ='001' THEN score ELSE 0 END)/SUM(CASE C# WHEN '001' THEN 1 ELSE 0 END) AS 企业管理平均分
98. ,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
99. ,SUM(CASE WHEN C# = '002' THEN score ELSE 0 END)/SUM(CASE C# WHEN '002' THEN 1 ELSE 0 END) AS 马克思平均分
100. ,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
101. ,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
102. ,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
103. ,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
104. ,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 数据库及格百分数
105. FROM SC
106.
107. 21、查询不同老师所教不同课程平均分从高到低显示
108. SELECT max(Z.T#) AS 教师ID,MAX(Z.Tname) AS 教师姓名,C.C# AS 课程ＩＤ,MAX(C.Cname) AS 课程名称,AVG(Score) AS 平均成绩
109. FROM SC AS T,Course AS C ,Teacher AS Z
110. where T.C#=C.C# and C.T#=Z.T#
111. GROUP BY C.C#
112. ORDER BY AVG(Score) DESC
113. 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（001），马克思（002），UML （003），数据库（004）
114. [学生ID],[学生姓名],企业管理,马克思,UML,数据库,平均成绩
115. SELECT DISTINCT top 3
116. SC.S# As 学生学号,
117. Student.Sname AS 学生姓名 ,
118. T1.score AS 企业管理,
119. T2.score AS 马克思,
120. T3.score AS UML,
121. T4.score AS 数据库,
122. ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) as 总分
123. FROM Student,SC LEFT JOIN SC AS T1
124. ON SC.S# = T1.S# AND T1.C# = '001'
125. LEFT JOIN SC AS T2
126. ON SC.S# = T2.S# AND T2.C# = '002'
127. LEFT JOIN SC AS T3
128. ON SC.S# = T3.S# AND T3.C# = '003'
129. LEFT JOIN SC AS T4
130. ON SC.S# = T4.S# AND T4.C# = '004'
131. WHERE student.S#=SC.S# and
132. ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)
133. NOT IN
134. (SELECT
135. DISTINCT
136. TOP 15 WITH TIES
137. ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)
138. FROM sc
139. LEFT JOIN sc AS T1
140. ON sc.S# = T1.S# AND T1.C# = 'k1'
141. LEFT JOIN sc AS T2
142. ON sc.S# = T2.S# AND T2.C# = 'k2'
143. LEFT JOIN sc AS T3
144. ON sc.S# = T3.S# AND T3.C# = 'k3'
145. LEFT JOIN sc AS T4
146. ON sc.S# = T4.S# AND T4.C# = 'k4'
147. ORDER BY ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) DESC);
148.
149. 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],[ <60]
150. SELECT SC.C# as 课程ID, Cname as 课程名称
151. ,SUM(CASE WHEN score BETWEEN 85 AND 100 THEN 1 ELSE 0 END) AS [100 - 85]
152. ,SUM(CASE WHEN score BETWEEN 70 AND 85 THEN 1 ELSE 0 END) AS [85 - 70]
153. ,SUM(CASE WHEN score BETWEEN 60 AND 70 THEN 1 ELSE 0 END) AS [70 - 60]
154. ,SUM(CASE WHEN score < 60 THEN 1 ELSE 0 END) AS [60 -]
155. FROM SC,Course
156. where SC.C#=Course.C#
157. GROUP BY SC.C#,Cname;
158.
159. 24、查询学生平均成绩及其名次
160. SELECT 1+(SELECT COUNT( distinct 平均成绩)
161. FROM (SELECT S#,AVG(score) AS 平均成绩
162. FROM SC
163. GROUP BY S#
164. ) AS T1
165. WHERE 平均成绩 > T2.平均成绩) as 名次,
166. S# as 学生学号,平均成绩
167. FROM (SELECT S#,AVG(score) 平均成绩
168. FROM SC
169. GROUP BY S#
170. ) AS T2
171. ORDER BY 平均成绩 desc;
172.
173. 25、查询各科成绩前三名的记录:(不考虑成绩并列情况)
174. SELECT t1.S# as 学生ID,t1.C# as 课程ID,Score as 分数
175. FROM SC t1
176. WHERE score IN (SELECT TOP 3 score
177. FROM SC
178. WHERE t1.C#= C#
179. ORDER BY score DESC
180. )
181. ORDER BY t1.C#;
182. 26、查询每门课程被选修的学生数
183. select c#,count(S#) from sc group by C#;
184. 27、查询出只选修了一门课程的全部学生的学号和姓名
185. select SC.S#,Student.Sname,count(C#) AS 选课数
186. from SC ,Student
187. where SC.S#=Student.S# group by SC.S# ,Student.Sname having count(C#)=1;
188. 28、查询男生、女生人数
189. Select count(Ssex) as 男生人数 from Student group by Ssex having Ssex='男';
190. Select count(Ssex) as 女生人数 from Student group by Ssex having Ssex='女'；
191. 29、查询姓“张”的学生名单
192. SELECT Sname FROM Student WHERE Sname like '张%';
193. 30、查询同名同性学生名单，并统计同名人数
194. select Sname,count(*) from Student group by Sname having count(*)>1;
195. 31、1981年出生的学生名单(注：Student表中Sage列的类型是datetime)
196. select Sname, CONVERT(char (11),DATEPART(year,Sage)) as age
197. from student
198. where CONVERT(char(11),DATEPART(year,Sage))='1981';
199. 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
200. Select C#,Avg(score) from SC group by C# order by Avg(score),C# DESC ;
201. 33、查询平均成绩大于85的所有学生的学号、姓名和平均成绩
202. select Sname,SC.S# ,avg(score)
203. from Student,SC
204. where Student.S#=SC.S# group by SC.S#,Sname having avg(score)>85;
205. 34、查询课程名称为“数据库”，且分数低于60的学生姓名和分数
206. Select Sname,isnull(score,0)
207. from Student,SC,Course
208. where SC.S#=Student.S# and SC.C#=Course.C# and Course.Cname='数据库'and score <60;
209. 35、查询所有学生的选课情况；
210. SELECT SC.S#,SC.C#,Sname,Cname
211. FROM SC,Student,Course
212. where SC.S#=Student.S# and SC.C#=Course.C# ;
213. 36、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；
214. SELECT distinct student.S#,student.Sname,SC.C#,SC.score
215. FROM student,Sc
216. WHERE SC.score>=70 AND SC.S#=student.S#;
217. 37、查询不及格的课程，并按课程号从大到小排列
218. select c# from sc where scor e <60 order by C# ;
219. 38、查询课程编号为003且课程成绩在80分以上的学生的学号和姓名；
220. select SC.S#,Student.Sname from SC,Student where SC.S#=Student.S# and Score>80 and C#='003';
221. 39、求选了课程的学生人数
222. select count(*) from sc;
223. 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
224. select Student.Sname,score
225. from Student,SC,Course C,Teacher
226. where Student.S#=SC.S# and SC.C#=C.C# and C.T#=Teacher.T# and Teacher.Tname='叶平' and SC.score=(select max(score)from SC where C#=C.C# );
227. 41、查询各个课程及相应的选修人数
228. select count(*) from sc group by C#;
229. 42、查询不同课程成绩相同的学生的学号、课程号、学生成绩
230. select distinct A.S#,B.score from SC A ,SC B where A.Score=B.Score and A.C# <>B.C# ;
231. 43、查询每门功成绩最好的前两名
232. SELECT t1.S# as 学生ID,t1.C# as 课程ID,Score as 分数
233. FROM SC t1
234. WHERE score IN (SELECT TOP 2 score
235. FROM SC
236. WHERE t1.C#= C#
237. ORDER BY score DESC
238. )
239. ORDER BY t1.C#;
240. 44、统计每门课程的学生选修人数（超过10人的课程才统计）。要求输出课程号和选修人数，查询结果按人数降序排列，查询结果按人数降序排列，若人数相同，按课程号升序排列
241. select C# as 课程号,count(*) as 人数
242. from sc
243. group by C#
244. order by count(*) desc,c#
245. 45、检索至少选修两门课程的学生学号
246. select S#
247. from sc
248. group by s#
249. having count(*) > = 2
250. 46、查询全部学生都选修的课程的课程号和课程名
251. select C#,Cname
252. from Course
253. where C# in (select c# from sc group by c#)
254. 47、查询没学过“叶平”老师讲授的任一门课程的学生姓名
255. 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='叶平');
256. 48、查询两门以上不及格课程的同学的学号及其平均成绩
257. 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#;
258. 49、检索“004”课程分数小于60，按分数降序排列的同学学号
259. select S# from SC where C#='004'and score <60 order by score desc;
260. 50、删除“002”同学的“001”课程的成绩
261. delete from Sc where S#='001'and C#='001';
1. Student(S#,Sname,Sage,Ssex) 学生表
2. Course(C#,Cname,T#) 课程表
3. SC(S#,C#,score) 成绩表
4. Teacher(T#,Tname) 教师表
5.
6. 问题：
7. 1、查询“001”课程比“002”课程成绩高的所有学生的学号；
8. select a.S# from (select s#,score from SC where C#='001') a,(select s#,score
9. from SC where C#='002') b
10. where a.score>b.score and a.s#=b.s#;
11. 2、查询平均成绩大于60分的同学的学号和平均成绩；
12. select S#,avg(score)
13. from sc
14. group by S# having avg(score) >60;
15. 3、查询所有同学的学号、姓名、选课数、总成绩；
16. select Student.S#,Student.Sname,count(SC.C#),sum(score)
17. from Student left Outer join SC on Student.S#=SC.S#
18. group by Student.S#,Sname
19. 4、查询姓“李”的老师的个数；
20. select count(distinct(Tname))
21. from Teacher
22. where Tname like '李%';
23. 5、查询没学过“叶平”老师课的同学的学号、姓名；
24. select Student.S#,Student.Sname
25. from Student
26. 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');
27. 6、查询学过“001”并且也学过编号“002”课程的同学的学号、姓名；
28. 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');
29. 7、查询学过“叶平”老师所教的所有课的同学的学号、姓名；
30. select S#,Sname
31. from Student
32. where S# in (select S# from SC ,Course ,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'));
33. 8、查询课程编号“002”的成绩比课程编号“001”课程低的所有同学的学号、姓名；
34. 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
35. from Student,SC where Student.S#=SC.S# and C#='001') S_2 where score2 <score;
36. 9、查询所有课程成绩小于60分的同学的学号、姓名；
37. select S#,Sname
38. from Student
39. where S# not in (select Student.S# from Student,SC where S.S#=SC.S# and score>60);
40. 10、查询没有学全所有课的同学的学号、姓名；
41. select Student.S#,Student.Sname
42. from Student,SC
43. where Student.S#=SC.S# group by Student.S#,Student.Sname having count(C#) <(select count(C#) from Course);
44.
45. 11、查询至少有一门课与学号为“1001”的同学所学相同的同学的学号和姓名；
46. select S#,Sname from Student,SC where Student.S#=SC.S# and C# in select C# from SC where S#='1001';
47. 12、查询至少学过学号为“001”同学所有一门课的其他同学学号和姓名；
48. select distinct SC.S#,Sname
49. from Student,SC
50. where Student.S#=SC.S# and C# in (select C# from SC where S#='001');
51. 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；
52. update SC set score=(select avg(SC_2.score)
53. from SC SC_2
54. where SC_2.C#=SC.C# ) from Course,Teacher where Course.C#=SC.C# and Course.T#=Teacher.T# and Teacher.Tname='叶平');
55. 14、查询和“1002”号的同学学习的课程完全相同的其他同学学号和姓名；
56. select S# from SC where C# in (select C# from SC where S#='1002')
57. group by S# having count(*)=(select count(*) from SC where S#='1002');
58. 15、删除学习“叶平”老师课的SC表记录；
59. Delect SC
60. from course ,Teacher
61. where Course.C#=SC.C# and Course.T#= Teacher.T# and Tname='叶平';
62. 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“003”课程的同学学号、2、
63. 号课的平均成绩；
64. Insert SC select S#,'002',(Select avg(score)
65. from SC where C#='002') from Student where S# not in (Select S# from SC where C#='002');
66. 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,企业管理,英语,有效课程数,有效平均分
67. SELECT S# as 学生ID
68. ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='004') AS 数据库
69. ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='001') AS 企业管理
70. ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='006') AS 英语
71. ,COUNT(*) AS 有效课程数, AVG(t.score) AS 平均成绩
72. FROM SC AS t
73. GROUP BY S#
74. ORDER BY avg(t.score)
75. 18、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
76. SELECT L.C# As 课程ID,L.score AS 最高分,R.score AS 最低分
77. FROM SC L ,SC AS R
78. WHERE L.C# = R.C# and
79. L.score = (SELECT MAX(IL.score)
80. FROM SC AS IL,Student AS IM
81. WHERE L.C# = IL.C# and IM.S#=IL.S#
82. GROUP BY IL.C#)
83. AND
84. R.Score = (SELECT MIN(IR.score)
85. FROM SC AS IR
86. WHERE R.C# = IR.C#
87. GROUP BY IR.C#
88. );
89. 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
90. SELECT t.C# AS 课程号,max(course.Cname)AS 课程名,isnull(AVG(score),0) AS 平均成绩
91. ,100 * SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) AS 及格百分数
92. FROM SC T,Course
93. where t.C#=course.C#
94. GROUP BY t.C#
95. ORDER BY 100 * SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) DESC
96. 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（001），马克思（002），OO&UML （003），数据库（004）
97. SELECT SUM(CASE WHEN C# ='001' THEN score ELSE 0 END)/SUM(CASE C# WHEN '001' THEN 1 ELSE 0 END) AS 企业管理平均分
98. ,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
99. ,SUM(CASE WHEN C# = '002' THEN score ELSE 0 END)/SUM(CASE C# WHEN '002' THEN 1 ELSE 0 END) AS 马克思平均分
100. ,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
101. ,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
102. ,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
103. ,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
104. ,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 数据库及格百分数
105. FROM SC
106.
107. 21、查询不同老师所教不同课程平均分从高到低显示
108. SELECT max(Z.T#) AS 教师ID,MAX(Z.Tname) AS 教师姓名,C.C# AS 课程ＩＤ,MAX(C.Cname) AS 课程名称,AVG(Score) AS 平均成绩
109. FROM SC AS T,Course AS C ,Teacher AS Z
110. where T.C#=C.C# and C.T#=Z.T#
111. GROUP BY C.C#
112. ORDER BY AVG(Score) DESC
113. 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（001），马克思（002），UML （003），数据库（004）
114. [学生ID],[学生姓名],企业管理,马克思,UML,数据库,平均成绩
115. SELECT DISTINCT top 3
116. SC.S# As 学生学号,
117. Student.Sname AS 学生姓名 ,
118. T1.score AS 企业管理,
119. T2.score AS 马克思,
120. T3.score AS UML,
121. T4.score AS 数据库,
122. ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) as 总分
123. FROM Student,SC LEFT JOIN SC AS T1
124. ON SC.S# = T1.S# AND T1.C# = '001'
125. LEFT JOIN SC AS T2
126. ON SC.S# = T2.S# AND T2.C# = '002'
127. LEFT JOIN SC AS T3
128. ON SC.S# = T3.S# AND T3.C# = '003'
129. LEFT JOIN SC AS T4
130. ON SC.S# = T4.S# AND T4.C# = '004'
131. WHERE student.S#=SC.S# and
132. ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)
133. NOT IN
134. (SELECT
135. DISTINCT
136. TOP 15 WITH TIES
137. ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)
138. FROM sc
139. LEFT JOIN sc AS T1
140. ON sc.S# = T1.S# AND T1.C# = 'k1'
141. LEFT JOIN sc AS T2
142. ON sc.S# = T2.S# AND T2.C# = 'k2'
143. LEFT JOIN sc AS T3
144. ON sc.S# = T3.S# AND T3.C# = 'k3'
145. LEFT JOIN sc AS T4
146. ON sc.S# = T4.S# AND T4.C# = 'k4'
147. ORDER BY ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) DESC);
148.
149. 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],[ <60]
150. SELECT SC.C# as 课程ID, Cname as 课程名称
151. ,SUM(CASE WHEN score BETWEEN 85 AND 100 THEN 1 ELSE 0 END) AS [100 - 85]
152. ,SUM(CASE WHEN score BETWEEN 70 AND 85 THEN 1 ELSE 0 END) AS [85 - 70]
153. ,SUM(CASE WHEN score BETWEEN 60 AND 70 THEN 1 ELSE 0 END) AS [70 - 60]
154. ,SUM(CASE WHEN score < 60 THEN 1 ELSE 0 END) AS [60 -]
155. FROM SC,Course
156. where SC.C#=Course.C#
157. GROUP BY SC.C#,Cname;
158.
159. 24、查询学生平均成绩及其名次
160. SELECT 1+(SELECT COUNT( distinct 平均成绩)
161. FROM (SELECT S#,AVG(score) AS 平均成绩
162. FROM SC
163. GROUP BY S#
164. ) AS T1
165. WHERE 平均成绩 > T2.平均成绩) as 名次,
166. S# as 学生学号,平均成绩
167. FROM (SELECT S#,AVG(score) 平均成绩
168. FROM SC
169. GROUP BY S#
170. ) AS T2
171. ORDER BY 平均成绩 desc;
172.
173. 25、查询各科成绩前三名的记录:(不考虑成绩并列情况)
174. SELECT t1.S# as 学生ID,t1.C# as 课程ID,Score as 分数
175. FROM SC t1
176. WHERE score IN (SELECT TOP 3 score
177. FROM SC
178. WHERE t1.C#= C#
179. ORDER BY score DESC
180. )
181. ORDER BY t1.C#;
182. 26、查询每门课程被选修的学生数
183. select c#,count(S#) from sc group by C#;
184. 27、查询出只选修了一门课程的全部学生的学号和姓名
185. select SC.S#,Student.Sname,count(C#) AS 选课数
186. from SC ,Student
187. where SC.S#=Student.S# group by SC.S# ,Student.Sname having count(C#)=1;
188. 28、查询男生、女生人数
189. Select count(Ssex) as 男生人数 from Student group by Ssex having Ssex='男';
190. Select count(Ssex) as 女生人数 from Student group by Ssex having Ssex='女'；
191. 29、查询姓“张”的学生名单
192. SELECT Sname FROM Student WHERE Sname like '张%';
193. 30、查询同名同性学生名单，并统计同名人数
194. select Sname,count(*) from Student group by Sname having count(*)>1;
195. 31、1981年出生的学生名单(注：Student表中Sage列的类型是datetime)
196. select Sname, CONVERT(char (11),DATEPART(year,Sage)) as age
197. from student
198. where CONVERT(char(11),DATEPART(year,Sage))='1981';
199. 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
200. Select C#,Avg(score) from SC group by C# order by Avg(score),C# DESC ;
201. 33、查询平均成绩大于85的所有学生的学号、姓名和平均成绩
202. select Sname,SC.S# ,avg(score)
203. from Student,SC
204. where Student.S#=SC.S# group by SC.S#,Sname having avg(score)>85;
205. 34、查询课程名称为“数据库”，且分数低于60的学生姓名和分数
206. Select Sname,isnull(score,0)
207. from Student,SC,Course
208. where SC.S#=Student.S# and SC.C#=Course.C# and Course.Cname='数据库'and score <60;
209. 35、查询所有学生的选课情况；
210. SELECT SC.S#,SC.C#,Sname,Cname
211. FROM SC,Student,Course
212. where SC.S#=Student.S# and SC.C#=Course.C# ;
213. 36、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；
214. SELECT distinct student.S#,student.Sname,SC.C#,SC.score
215. FROM student,Sc
216. WHERE SC.score>=70 AND SC.S#=student.S#;
217. 37、查询不及格的课程，并按课程号从大到小排列
218. select c# from sc where scor e <60 order by C# ;
219. 38、查询课程编号为003且课程成绩在80分以上的学生的学号和姓名；
220. select SC.S#,Student.Sname from SC,Student where SC.S#=Student.S# and Score>80 and C#='003';
221. 39、求选了课程的学生人数
222. select count(*) from sc;
223. 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
224. select Student.Sname,score
225. from Student,SC,Course C,Teacher
226. where Student.S#=SC.S# and SC.C#=C.C# and C.T#=Teacher.T# and Teacher.Tname='叶平' and SC.score=(select max(score)from SC where C#=C.C# );
227. 41、查询各个课程及相应的选修人数
228. select count(*) from sc group by C#;
229. 42、查询不同课程成绩相同的学生的学号、课程号、学生成绩
230. select distinct A.S#,B.score from SC A ,SC B where A.Score=B.Score and A.C# <>B.C# ;
231. 43、查询每门功成绩最好的前两名
232. SELECT t1.S# as 学生ID,t1.C# as 课程ID,Score as 分数
233. FROM SC t1
234. WHERE score IN (SELECT TOP 2 score
235. FROM SC
236. WHERE t1.C#= C#
237. ORDER BY score DESC
238. )
239. ORDER BY t1.C#;
240. 44、统计每门课程的学生选修人数（超过10人的课程才统计）。要求输出课程号和选修人数，查询结果按人数降序排列，查询结果按人数降序排列，若人数相同，按课程号升序排列
241. select C# as 课程号,count(*) as 人数
242. from sc
243. group by C#
244. order by count(*) desc,c#
245. 45、检索至少选修两门课程的学生学号
246. select S#
247. from sc
248. group by s#
249. having count(*) > = 2
250. 46、查询全部学生都选修的课程的课程号和课程名
251. select C#,Cname
252. from Course
253. where C# in (select c# from sc group by c#)
254. 47、查询没学过“叶平”老师讲授的任一门课程的学生姓名
255. 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='叶平');
256. 48、查询两门以上不及格课程的同学的学号及其平均成绩
257. 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#;
258. 49、检索“004”课程分数小于60，按分数降序排列的同学学号
259. select S# from SC where C#='004'and score <60 order by score desc;
260. 50、删除“002”同学的“001”课程的成绩
261. delete from Sc where S#='001'and C#='001';本文章为转载内容，我们尊重原作者对文章享有的著作权。如有内容错误或侵权问题，欢迎原作者联系我们进行内容更正或删除文章。
