题干:
1 create table student( 2 sno varchar2(10) primary key, 3 sname varchar2(20), 4 sage number(2), 5 ssex varchar2(5) 6 ); 7 create table teacher( 8 tno varchar2(10) primary key, 9 tname varchar2(20) 10 ); 11 create table course( 12 cno varchar2(10), 13 cname varchar2(20), 14 tno varchar2(20), 15 constraint pk_course primary key (cno,tno) 16 ); 17 create table sc( 18 sno varchar2(10), 19 cno varchar2(10), 20 score number(4,2), 21 constraint pk_sc primary key (sno,cno) 22 ); 23 /*******初始化学生表的数据******/ 24 insert into student values ('s001','张三',23,'男'); 25 insert into student values ('s002','李四',23,'男'); 26 insert into student values ('s003','吴鹏',25,'男'); 27 insert into student values ('s004','琴沁',20,'女'); 28 insert into student values ('s005','王丽',20,'女'); 29 insert into student values ('s006','李波',21,'男'); 30 insert into student values ('s007','刘玉',21,'男'); 31 insert into student values ('s008','萧蓉',21,'女'); 32 insert into student values ('s009','陈萧晓',23,'女'); 33 insert into student values ('s010','陈美',22,'女'); 34 commit; 35 /******************初始化教师表***********************/ 36 insert into teacher values ('t001', '刘阳'); 37 insert into teacher values ('t002', '谌燕'); 38 insert into teacher values ('t003', '胡明星'); 39 commit; 40 /***************初始化课程表****************************/ 41 insert into course values ('c001','J2SE','t002'); 42 insert into course values ('c002','Java Web','t002'); 43 insert into course values ('c003','SSH','t001'); 44 insert into course values ('c004','Oracle','t001'); 45 insert into course values ('c005','SQL SERVER 2005','t003'); 46 insert into course values ('c006','C#','t003'); 47 insert into course values ('c007','JavaScript','t002'); 48 insert into course values ('c008','DIV+CSS','t001'); 49 insert into course values ('c009','PHP','t003'); 50 insert into course values ('c010','EJB3.0','t002'); 51 commit; 52 /***************初始化成绩表***********************/ 53 insert into sc values ('s001','c001',78.9); 54 insert into sc values ('s002','c001',80.9); 55 insert into sc values ('s003','c001',81.9); 56 insert into sc values ('s004','c001',60.9); 57 insert into sc values ('s001','c002',82.9); 58 insert into sc values ('s002','c002',72.9); 59 insert into sc values ('s003','c002',81.9); 60 insert into sc values ('s001','c003','59'); 61 commit;
题目:
练习:
注意:以下练习中的数据是根据初始化到数据库中的数据来写的SQL 语句,请大家务必注意。
1、查询“c001”课程比“c002”课程成绩高的所有学生的学号;
2、查询平均成绩大于60 分的同学的学号和平均成绩;
3、查询所有同学的学号、姓名、选课数、总成绩;
4、查询姓“刘”的老师的个数;
5、查询没学过“谌燕”老师课的同学的学号、姓名;
6、查询学过“c001”并且也学过编号“c002”课程的同学的学号、姓名;
7、查询学过“谌燕”老师所教的所有课的同学的学号、姓名;
8、查询课程编号“c002”的成绩比课程编号“c001”课程低的所有同学的学号、姓名;
9、查询所有课程成绩小于60 分的同学的学号、姓名;
10、查询没有学全所有课的同学的学号、姓名;
11、查询至少有一门课与学号为“s001”的同学所学相同的同学的学号和姓名;
12、查询至少学过学号为“s001”同学所有一门课的其他同学学号和姓名;
13、把“SC”表中“谌燕”老师教的课的成绩都更改为此课程的平均成绩;
14、查询和“s001”号的同学学习的课程完全相同的其他同学学号和姓名;
15、删除学习“谌燕”老师课的SC 表记录;
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“c002”课程的同学学号、“c002”号课的平均成绩;
17、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
18、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
19、查询不同老师所教不同课程平均分从高到低显示
20、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]
21、查询各科成绩前三名的记录:(不考虑成绩并列情况)
22、查询每门课程被选修的学生数
23、查询出只选修了一门课程的全部学生的学号和姓名
24、查询男生、女生人数
25、查询姓“张”的学生名单
26、查询同名同性学生名单,并统计同名人数
27、1981 年出生的学生名单(注:Student 表中Sage 列的类型是number)
28、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
29、查询平均成绩大于85 的所有学生的学号、姓名和平均成绩
30、查询课程名称为“数据库”,且分数低于60 的学生姓名和分数
31、查询所有学生的选课情况;
32、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;
33、查询不及格的课程,并按课程号从大到小排列
34、查询课程编号为c001 且课程成绩在80 分以上的学生的学号和姓名;
35、求选了课程的学生人数
36、查询选修“谌燕”老师所授课程的学生中,成绩最高的学生姓名及其成绩
37、查询各个课程及相应的选修人数
38、查询不同课程成绩相同的学生的学号、课程号、学生成绩
39、查询每门功课成绩最好的前两名
40、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,若人数相同,按课程号升序排列
41、检索至少选修两门课程的学生学号
42、查询全部学生都选修的课程的课程号和课程名
43、查询没学过“谌燕”老师讲授的任一门课程的学生姓名
44、查询两门以上不及格课程的同学的学号及其平均成绩
45、检索“c004”课程分数小于60,按分数降序排列的同学学号
46、删除“s002”同学的“c001”课程的成绩
参考答案:
1 1. 2 ********************************* 3 select a.* from 4 (select * from sc a where a.cno='c001') a, 5 (select * from sc b where b.cno='c002') b 6 where a.sno=b.sno and a.score > b.score; 7 ********************************* 8 select * from sc a 9 where a.cno='c001' 10 and exists(select * from sc b where b.cno='c002' and a.score>b.score 11 and a.sno = b.sno) 12 ********************************* 13 2. 14 ********************************* 15 select sno,avg(score) from sc group by sno having avg(score)>60; 16 ********************************* 17 3. 18 ********************************* 19 select a.*,s.sname from (select sno,sum(score),count(cno) from sc group by sno) a ,student s where a.sno=s.sno 20 ********************************* 21 4. 22 ********************************* 23 select count(*) from teacher where tname like '刘%'; 24 ********************************* 25 5. 26 ********************************* 27 select a.sno,a.sname from student a 28 where a.sno 29 not in 30 (select distinct s.sno 31 from sc s, 32 (select c.* 33 from course c , 34 (select tno 35 from teacher t 36 where tname='谌燕')t 37 where c.tno=t.tno) b 38 where s.cno = b.cno ) 39 ********************************* 40 select * from student st where st.sno not in 41 (select distinct sno from sc s join course c on s.cno=c.cno 42 join teacher t on c.tno=t.tno where tname='谌燕') 43 ********************************* 44 6. 45 ********************************* 46 select st.* from sc a 47 join sc b on a.sno=b.sno 48 join student st 49 on st.sno=a.sno 50 where a.cno='c001' and b.cno='c002' and st.sno=a.sno; 51 ********************************* 52 7. 53 ********************************* 54 select st.* from student st join sc s on st.sno=s.sno 55 join course c on s.cno=c.cno 56 join teacher t on c.tno=t.tno 57 where t.tname='谌燕' 58 ********************************* 59 8. 60 ********************************* 61 select * from student st 62 join sc a on st.sno=a.sno 63 join sc b on st.sno=b.sno 64 where a.cno='c002' and b.cno='c001' and a.score < b.score 65 ********************************* 66 9. 67 ********************************* 68 select st.*,s.score from student st 69 join sc s on st.sno=s.sno 70 join course c on s.cno=c.cno 71 where s.score <60 72 ********************************* 73 10. 74 ********************************* 75 select stu.sno,stu.sname,count(sc.cno) from student stu 76 left join sc on stu.sno=sc.sno 77 group by stu.sno,stu.sname 78 having count(sc.cno)<(select count(distinct cno)from course) 79 =================================== 80 select * from student where sno in 81 (select sno from 82 (select stu.sno,c.cno from student stu 83 cross join course c 84 minus 85 select sno,cno from sc) 86 ) 87 =================================== 88 ********************************* 89 11. 90 ********************************* 91 select st.* from student st, 92 (select distinct a.sno from 93 (select * from sc) a, 94 (select * from sc where sc.sno='s001') b 95 where a.cno=b.cno) h 96 where st.sno=h.sno and st.sno<>'s001' 97 ********************************* 98 12. 99 ********************************* 100 select * from sc 101 left join student st 102 on st.sno=sc.sno 103 where sc.sno<>'s001' 104 and sc.cno in 105 (select cno from sc 106 where sno='s001') 107 ********************************* 108 13. 109 ********************************* 110 update sc c set score=(select avg(c.score) from course a,teacher b 111 where a.tno=b.tno 112 and b.tname='谌燕' 113 and a.cno=c.cno 114 group by c.cno) 115 where cno in( 116 select cno from course a,teacher b 117 where a.tno=b.tno 118 and b.tname='谌燕') 119 ********************************* 120 14. 121 ********************************* 122 select* from sc where sno<>'s001' 123 minus 124 ( 125 select* from sc 126 minus 127 select * from sc where sno='s001' 128 ) 129 ********************************* 130 15. 131 ********************************* 132 delete from sc 133 where sc.cno in 134 ( 135 select cno from course c 136 left join teacher t on c.tno=t.tno 137 where t.tname='谌燕' 138 ) 139 ********************************* 140 16. 141 ********************************* 142 insert into sc (sno,cno,score) 143 select distinct st.sno,sc.cno,(select avg(score)from sc where cno='c002') 144 from student st,sc 145 where not exists 146 (select * from sc where cno='c002' and sc.sno=st.sno) and sc.cno='c002'; 147 ********************************* 148 17. 149 ********************************* 150 select cno ,max(score),min(score) from sc group by cno; 151 ********************************* 152 18. 153 ********************************* 154 select cno,avg(score),sum(case when score>=60 then 1 else 0 end)/count(*) 155 as 及格率 156 from sc group by cno 157 order by avg(score) , 及格率desc 158 ********************************* 159 19. 160 ********************************* 161 select max(t.tno),max(t.tname),max(c.cno),max(c.cname),c.cno,avg(score) from sc , course c,teacher t 162 where sc.cno=c.cno and c.tno=t.tno 163 group by c.cno 164 order by avg(score) desc 165 ********************************* 166 20. 167 ********************************* 168 select sc.cno,c.cname, 169 sum(case when score between 85 and 100 then 1 else 0 end) AS "[100-85]", 170 sum(case when score between 70 and 85 then 1 else 0 end) AS "[85-70]", 171 sum(case when score between 60 and 70 then 1 else 0 end) AS "[70-60]", 172 sum(case when score <60 then 1 else 0 end) AS "[<60]" 173 from sc, course c 174 where sc.cno=c.cno 175 group by sc.cno ,c.cname; 176 ********************************* 177 21. 178 ********************************* 179 select * from 180 (select sno,cno,score,row_number()over(partition by cno order by score desc) rn from sc) 181 where rn<4 182 ********************************* 183 22. 184 ********************************* 185 select cno,count(sno)from sc group by cno; 186 ********************************* 187 23. 188 ********************************* 189 select sc.sno,st.sname,count(cno) from student st 190 left join sc 191 on sc.sno=st.sno 192 group by st.sname,sc.sno having count(cno)=1; 193 ********************************* 194 24. 195 ********************************* 196 select ssex,count(*)from student group by ssex; 197 ********************************* 198 25. 199 ********************************* 200 select * from student where sname like '张%'; 201 ********************************* 202 26. 203 ********************************* 204 select sname,count(*)from student group by sname having count(*)>1; 205 ********************************* 206 27. 207 ********************************* 208 select sno,sname,sage,ssex from student t where to_char(sysdate,'yyyy')-sage =1988 209 ********************************* 210 28. 211 ********************************* 212 select cno,avg(score) from sc group by cno order by avg(score)asc,cno desc; 213 ********************************* 214 29. 215 ********************************* 216 select st.sno,st.sname,avg(score) from student st 217 left join sc 218 on sc.sno=st.sno 219 group by st.sno,st.sname having avg(score)>85; 220 ********************************* 221 30. 222 ********************************* 223 select sname,score from student st,sc,course c 224 where st.sno=sc.sno and sc.cno=c.cno and c.cname='Oracle' and sc.score<60 225 ********************************* 226 31. 227 ********************************* 228 select st.sno,st.sname,c.cname from student st,sc,course c 229 where sc.sno=st.sno and sc.cno=c.cno; 230 ********************************* 231 32. 232 ********************************* 233 select st.sname,c.cname,sc.score from student st,sc,course c 234 where sc.sno=st.sno and sc.cno=c.cno and sc.score>70 235 ********************************* 236 33. 237 ********************************* 238 select sc.sno,c.cname,sc.score from sc,course c 239 where sc.cno=c.cno and sc.score<60 order by sc.cno desc; 240 ********************************* 241 34. 242 ********************************* 243 select st.sno,st.sname,sc.score from sc,student st 244 where sc.sno=st.sno and cno='c001' and score>80; 245 ********************************* 246 35. 247 ********************************* 248 select count(distinct sno) from sc; 249 ********************************* 250 36. 251 ********************************* 252 select st.sname,score from student st,sc ,course c,teacher t 253 where 254 st.sno=sc.sno and sc.cno=c.cno and c.tno=t.tno 255 and t.tname='谌燕' and sc.score= 256 (select max(score)from sc where sc.cno=c.cno) 257 ********************************* 258 37. 259 ********************************* 260 select cno,count(sno) from sc group by cno; 261 ********************************* 262 38. 263 ********************************* 264 select a.* from sc a ,sc b where a.score=b.score and a.cno<>b.cno 265 ********************************* 266 39. 267 ********************************* 268 select * from ( 269 select sno,cno,score,row_number()over(partition by cno order by score desc) my_rn from sc t 270 ) 271 where my_rn<=2 272 ********************************* 273 40. 274 ********************************* 275 select cno,count(sno) from sc group by cno 276 having count(sno)>10 277 order by count(sno) desc,cno asc; 278 ********************************* 279 41. 280 ********************************* 281 select sno from sc group by sno having count(cno)>1; 282 || 283 select sno from sc group by sno having count(sno)>1; 284 ********************************* 285 42. 286 ********************************* 287 select distinct(c.cno),c.cname from course c ,sc 288 where sc.cno=c.cno 289 || 290 select cno,cname from course c 291 where c.cno in 292 (select cno from sc group by cno) 293 ********************************* 294 43. 295 ********************************* 296 select st.sname from student st 297 where st.sno not in 298 (select distinct sc.sno from sc,course c,teacher t 299 where sc.cno=c.cno and c.tno=t.tno and t.tname='谌燕') 300 ********************************* 301 44. 302 ********************************* 303 select sno,avg(score)from sc 304 where sno in 305 (select sno from sc where sc.score<60 306 group by sno having count(sno)>1 307 ) group by sno 308 ********************************* 309 45. 310 ********************************* 311 select sno from sc where cno='c004' and score<90 order by score desc; 312 ********************************* 313 46. 314 ********************************* 315 delete from sc where sno='s002' and cno='c001'; 316 *********************************
我的解答-前12题
1 SQL> --1、查询“c001”课程比“c002”课程成绩高的所有学生的学号; 2 SQL> select a.sno from sc a, sc b where a.cno = 'c001' and b.cno = 'c002' and a.score > b.score and a.sno = b.sno; 3 SNO 4 ---------- 5 s002 6 7 SQL> --2、查询平均成绩大于60 分的同学的学号和平均成绩; 8 9 SQL> select sno, avg(score) from sc group by sno having avg(score) > 60; 10 SNO AVG(SCORE) 11 ---------- ---------- 12 s003 81.9 13 s004 60.9 14 s001 73.6 15 s002 76.9 16 17 SQL> --3、查询所有同学的学号、姓名、选课数、总成绩; 18 SQL> select s.sno, s.sname, count(cno), sum(score) from sc c, student s where c.sno = s.sno group by s.sno, s.sname; 19 SNO SNAME COUNT(CNO) SUM(SCORE) 20 ---------- -------------------- ---------- ---------- 21 s001 张三 3 220.8 22 s003 吴鹏 2 163.8 23 s004 琴沁 1 60.9 24 s002 李四 2 153.8 25 26 SQL> ----4、查询姓“刘”的老师的个数; 27 SQL> select count(1) from teacher where tname like '刘%' group by tname; 28 COUNT(1) 29 ---------- 30 1 31 32 SQL> ----5、查询没学过“谌燕”老师课的同学的学号、姓名; 33 SQL> select sno, sname from student where sno not in (select sno from sc c, teacher t, course o where c.cno = o.cno and o.tno = t.tno and t.tname = '谌燕'); 34 SNO SNAME 35 ---------- -------------------- 36 s005 王丽 37 s006 李波 38 s007 刘玉 39 s008 萧蓉 40 s009 陈萧晓 41 s010 陈美 42 6 rows selected 43 44 SQL> --6、查询学过“c001”并且也学过编号“c002”课程的同学的学号、姓名 45 SQL> select s.sno, s.sname from sc a, sc b, student s where a.cno = 'c001' and b.cno = 'c002' and s.sno =a.sno; 46 SNO SNAME 47 ---------- -------------------- 48 s001 张三 49 s001 张三 50 s001 张三 51 s002 李四 52 s002 李四 53 s002 李四 54 s003 吴鹏 55 s003 吴鹏 56 s003 吴鹏 57 s004 琴沁 58 s004 琴沁 59 s004 琴沁 60 12 rows selected 61 62 SQL> select * from sc a, sc b where a.cno = 'c001' and b.cno = 'c002'; 63 SNO CNO SCORE SNO CNO SCORE 64 ---------- ---------- ------ ---------- ---------- ------ 65 s001 c001 78.90 s001 c002 82.90 66 s002 c001 80.90 s001 c002 82.90 67 s003 c001 81.90 s001 c002 82.90 68 s004 c001 60.90 s001 c002 82.90 69 s001 c001 78.90 s002 c002 72.90 70 s002 c001 80.90 s002 c002 72.90 71 s003 c001 81.90 s002 c002 72.90 72 s004 c001 60.90 s002 c002 72.90 73 s001 c001 78.90 s003 c002 81.90 74 s002 c001 80.90 s003 c002 81.90 75 s003 c001 81.90 s003 c002 81.90 76 s004 c001 60.90 s003 c002 81.90 77 12 rows selected 78 79 SQL> select * from sc a, sc b where a.cno = 'c001' and b.cno = 'c002' and a.sno = b.sno; 80 SNO CNO SCORE SNO CNO SCORE 81 ---------- ---------- ------ ---------- ---------- ------ 82 s001 c001 78.90 s001 c002 82.90 83 s002 c001 80.90 s002 c002 72.90 84 s003 c001 81.90 s003 c002 81.90 85 86 SQL> select s.sno, s.sname from sc a, sc b, student s where a.cno = 'c001' and b.cno = 'c002' and a.sno =b.sno and s.sno =a.sno; 87 SNO SNAME 88 ---------- -------------------- 89 s001 张三 90 s002 李四 91 s003 吴鹏 92 93 SQL> -- 7、查询学过“谌燕”老师所教的所有课的同学的学号、姓名; 94 SQL> select o.cno from teacher t, course o where o.tno = t.tno and t.tname = '谌燕'; 95 CNO 96 ---------- 97 c001 98 c002 99 c007 100 c010 101 102 SQL> select s.sno, s.sname from student s, teacher t, course o, sc c where o.tno = t.tno and s.sno = c.sno and c.cno = o.cno and t.tname = '谌燕'; 103 SNO SNAME 104 ---------- -------------------- 105 s001 张三 106 s001 张三 107 s002 李四 108 s002 李四 109 s003 吴鹏 110 s003 吴鹏 111 s004 琴沁 112 7 rows selected 113 114 SQL> -- 8、查询课程编号“c002”的成绩比课程编号“c001”课程低的所有同学的学号、姓名; 115 SQL> select s.sno, s.sname from student s, sc a, sc b where a.cno = 'c002' and b.cno = 'c001' and a.score < b.score and a.sno = b.sno 116 2 and s.sno = a.sno; 117 SNO SNAME 118 ---------- -------------------- 119 s002 李四 120 121 SQL> -- 9、查询所有课程成绩小于60 分的同学的学号、姓名; 122 SQL> select s.sno, s.sname from student s, sc c where 123 2 c.score < 60 and s.sno = c.sno; 124 SNO SNAME 125 ---------- -------------------- 126 s001 张三 127 128 SQL> -- 10、查询没有学全所有课的同学的学号、姓名; 129 SQL> select s.sno, s.sname from student s, sc c where s.sno = c.sno 130 2 group by s.sno, s.sname having count (c.cno) < (select count(cno) from course); 131 SNO SNAME 132 ---------- -------------------- 133 s001 张三 134 s003 吴鹏 135 s004 琴沁 136 s002 李四 137 138 SQL> -- 11、查询至少有一门课与学号为“s001”的同学所学相同的同学的学号和姓名; 139 SQL> select s.sno s.sname from student s, sc c where s.sno = c.sno 140 2 and c.cno in(select cno from sc where sno = 's001'); 141 select s.sno s.sname from student s, sc c where s.sno = c.sno 142 and c.cno in(select cno from sc where sno = 's001') 143 ORA-00923: 未找到要求的 FROM 关键字 144 145 SQL> select distinct(s.sno), s.sname from student s, sc c where s.sno = c.sno 146 2 and c.cno in(select cno from sc where sno = 's001'); 147 SNO SNAME 148 ---------- -------------------- 149 s001 张三 150 s001 张三 151 s001 张三 152 s002 李四 153 s002 李四 154 s003 吴鹏 155 s003 吴鹏 156 s004 琴沁 157 8 rows selected 158 159 SQL> select distinct(s.sno), s.sname from student s, sc c where s.sno = c.sno 160 2 and c.cno in(select cno from sc where sno = 's001'); 161 SNO SNAME 162 ---------- -------------------- 163 s001 张三 164 s003 吴鹏 165 s004 琴沁 166 s002 李四 167 168 SQL> -- 12、查询至少学过学号为“s001”同学所有一门课的其他同学学号和姓名; 169 SQL> select distinct(s.sno), s.sname from student s, sc c where s.sno = c.sno 170 2 and c.cno in(select cno from sc where sno = 's001') and s.sno <> 's001'; 171 SNO SNAME 172 ---------- -------------------- 173 s003 吴鹏 174 s004 琴沁 175 s002 李四