数据库练习题 | 面试题 学生课程管理系统
环境:我这用的是MySQL 也可以用SQL Server这些,只不过建表语句和某些SQL语句语法不一样
代码及答案如下:
1 创建表和输入数据 2 CREATE DATABASE Test1; 3 USE Test1; 4 学生表（学号，姓名，性别，生日，班级） 5 CREATE TABLE STUDENT 6 (SNO VARCHAR(3) NOT NULL, 7 SNAME VARCHAR(4) NOT NULL, 8 SSEX VARCHAR(2) NOT NULL, 9 SBIRTHDAY DATETIME, 10 CLASS VARCHAR(5)); 11 12 13 课程（课程号，姓名，老师编号） 14 CREATE TABLE COURSE 15 ( CNO VARCHAR(5) NOT NULL, 16 CNAME VARCHAR(10) NOT NULL, 17 TNO VARCHAR(10) NOT NULL); 18 19 20 分数（学生编号，课程编号，分数） 21 CREATE TABLE SCORE 22 ( SNO VARCHAR(3) NOT NULL, 23 CNO VARCHAR(5) NOT NULL, 24 DEGREE NUMERIC(10, 1) NOT NULL) 25 26 27 老师（老师编号，老师姓名，生日，系名） 28 CREATE TABLE TEACHER 29 (TNO VARCHAR(3) NOT NULL, 30 TNAME VARCHAR(4) NOT NULL, TSEX VARCHAR(2) NOT NULL, 31 TBIRTHDAY DATETIME NOT NULL, PROF VARCHAR(6), 32 DEPART VARCHAR(10) NOT NULL) 33 DELETE FROM Student; 34 INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (108 ,'曾华' ,'男' ,'1977-09-01','95033'); 35 INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (105 ,'匡明' ,'男' ,'1975-10-02','95031'); 36 INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (107 ,'王丽' ,'女' ,'1976-01-23','95033'); 37 INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (101 ,'李军' ,'男' ,'1976-02-20','95033'); 38 INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (109 ,'王芳' ,'女' ,'1975-02-10','95031'); 39 INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (103 ,'陆君' ,'男' ,'1974-06-03','95031'); 40 41 INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('3-105' ,'计算机导论','825') 42 INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('3-245' ,'操作系统' ,'804'); 43 INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('6-166' ,'数据电路' ,'856'); 44 INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('9-888' ,'高等数学' ,'100'); 45 46 47 INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES ('103','3-245',86); 48 INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES ('105','3-245',75); 49 INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES ('109','3-245',68); 50 INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES ('103','3-105',92); 51 INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES ('105','3-105',88); 52 INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES ('109','3-105',76); 53 INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES ('101','3-105',64); 54 INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES ('107','3-105',91); 55 INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES ('108','3-105',78); 56 INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES ('101','6-166',85); 57 INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES ('107','6-106',79); 58 INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES ('108','6-166',81); 59 60 INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) 61 VALUES ('804','李诚','男','1958-12-02','副教授','计算机系'); 62 INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) 63 VALUES ('856','张旭','男','1969-03-12','讲师','电子工程系'); 64 INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) 65 VALUES ('825','王萍','女','1972-05-05','助教','计算机系'); 66 INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) 67 VALUES ('831','刘冰','女','1977-08-14','助教','电子工程系'); 68 69 70 71 # 练习题目 72 73 # 1、 查询Student表中的所有记录的Sname、Ssex和Class列。 74 SELECT SName,SSex,Class 75 FROM Student; 76 77 # 2、 查询教师所有的单位即不重复的Depart列。 78 SELECT Depart 79 FROM Teacher 80 GROUP BY Depart 81 82 83 # 3、 查询Student表的所有记录。 84 SELECT * 85 FROM Student; 86 87 # 4、 查询Score表中成绩在60到80之间的所有记录。 88 SELECT * 89 FROM Score 90 WHERE Degree BETWEEN 60 AND 80; 91 # 5、 查询Score表中成绩为85，86或88的记录。 92 SELECT * 93 FROM Score 94 WHERE Degree IN (85,86,88); 95 96 # 6、 查询Student表中“95031”班或性别为“女”的同学记录。 97 SELECT * 98 FROM Student 99 WHERE Class='95031' OR Ssex='女'; 100 101 # 7、 以Class降序查询Student表的所有记录 102 SELECT * 103 FROM Student 104 ORDER BY Class DESC; 105 106 # 8、 以Cno升序、Degree降序查询Score表的所有记录。 107 SELECT * 108 FROM Score 109 ORDER BY Cno,Degree DESC; 110 111 # 9、 查询“95031”班的学生人数。 112 SELECT COUNT(*) AS 人数 113 FROM Student 114 WHERE Class='95031'; 115 116 117 # 10、查询Score表中的最高分的学生学号和课程号。 118 SELECT Sno,Cno 119 FROM Score 120 ORDER BY Degree DESC 121 LIMIT 1; 122 123 # 11、查询‘3-105’号课程的平均分。 124 SELECT AVG(Degree) 125 FROM Score 126 WHERE Cno='3-105'; 127 128 # 12、查询Score表中至少有5名学生选修的并以3开头的课程的平均分数。 129 SELECT AVG(Degree) 130 FROM Score 131 WHERE Cno LIKE '3%' 132 HAVING COUNT(*)>5; 133 134 # 13、查询最低分大于70，最高分小于90的Sno列。 135 SELECT Sno 136 FROM Score 137 GROUP BY Sno 138 HAVING MIN(Degree)>70 AND MAX(Degree)<90; 139 140 # 14、查询所有学生的Sname、Cno和Degree列。 141 SELECT SName,Cno,Degree 142 FROM Student stu 143 INNER JOIN Score sco ON stu.Sno=sco.Sno 144 145 # 15、查询所有学生的Sno、Cname和Degree列。 146 SELECT Sno,CName,Degree 147 FROM Score s 148 INNER JOIN Course c ON s.Cno=c.Cno; 149 150 151 # 16、查询所有学生的Sname、Cname和Degree列。 152 SELECT SName,CName,Degree 153 FROM Score s 154 INNER JOIN Student stu ON s.Sno=stu.Sno 155 INNER JOIN Course c ON s.Cno = c.Cno 156 157 # 17、查询“95033”班所选课程的平均分。 158 SELECT AVG(Degree) 159 FROM Score 160 WHERE Sno IN( 161 SELECT Sno 162 FROM Student WHERE Class='95033' 163 ); 164 165 # 18、假设使用如下命令建立了一个grade表： 166 grade表将分数和对应等级进行比对 167 create TABLE grade( 168 low INT, 169 upp INT, 170 rank CHAR(1) 171 ); 172 173 INSERT INTO grade VALUES(90,100,'A'); 174 INSERT INTO grade VALUES(80,89,'B'); 175 INSERT INTO grade VALUES(70,79,'C'); 176 INSERT INTO grade VALUES(60,69,'D'); 177 INSERT INTO grade VALUES(0,59,'E'); 178 179 #现查询所有同学的Sno、Cno和rank列。 180 SELECT Sno,Cno,Rank AS 等级 181 FROM Score 182 INNER JOIN Grade ON Score.`DEGREE` BETWEEN Grade.`low` AND Grade.`upp` 183 184 185 # 19、查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录。 186 SELECT s1.* 187 FROM Score s1,Score s2 188 WHERE s1.Cno='3-105' AND s2.Cno='3-105' AND s2.Sno='109' AND s1.Degree>s2.`DEGREE` 189 190 # 20、查询score中选学一门以上课程的同学中分数为非最高分成绩的记录。 191 SELECT * 192 FROM Score s 193 WHERE Degree NOT IN( 194 SELECT MAX(Degree) FROM Score WHERE s.Sno=Score.Sno 195 ); 196 197 # 21、查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录。 198 SELECT * 199 FROM Score 200 WHERE Degree>( 201 SELECT Degree 202 FROM Score WHERE Sno='109' AND Cno='3-105' 203 ); 204 # 22、查询和学号为108的同学同年出生的所有学生的Sno、Sname和Sbirthday列 205 SELECT Sno,Sname,Sbirthday 206 FROM Student 207 WHERE YEAR(Sbirthday)=( 208 SELECT YEAR(Sbirthday) 209 FROM Student WHERE Sno='108' 210 ); 211 212 # 23、查询“张旭“教师任课的学生成绩。 213 SELECT * 214 FROM Score 215 WHERE Cno IN ( 216 SELECT Cno 217 FROM Course WHERE Tno = ( 218 SELECT Tno 219 FROM Teacher WHERE TName='张旭' 220 ) 221 ); 222 223 # 24、查询选修某课程的同学人数多于5人的教师姓名。 224 SELECT TName 225 FROM Teacher t 226 INNER JOIN Course c ON t.`TNO`=c.`TNO` 227 INNER JOIN Score s ON c.`CNO`=s.`CNO` 228 GROUP BY t.`TNO` 229 HAVING COUNT(*)>5 230 231 # 25、查询95033班和95031班全体学生的记录。 232 SELECT * 233 FROM Student 234 WHERE Class='95033' OR Class='95031'; 235 236 # 26、查询存在有85分以上成绩的课程Cno. 237 SELECT Cno 238 FROM Score 239 WHERE Degree>85 240 GROUP BY Cno 241 242 # 27、查询出“计算机系“教师所教课程的成绩表。 243 SELECT * 244 FROM Score 245 WHERE Cno IN( 246 SELECT Cno 247 FROM Course WHERE Tno IN ( 248 SELECT Tno 249 FROM Teacher WHERE Depart='计算机系' 250 ) 251 ); 252 253 254 # 28、查询“计算机系”与“电子工程系”不同职称的教师的Tname和Prof。 255 SELECT * 256 FROM Teacher 257 WHERE Depart='计算机系' OR Depart='电子工程系' 258 259 # 29、查询选修编号为“3-105“课程且成绩至少高于选修编号为“3-245”的同学的Cno、Sno和Degree,并按Degree从高到低次序排序。 260 SELECT s1.* 261 FROM Score s1,Score s2 262 WHERE s1.Cno='3-105' AND s2.Cno='3-245' AND s1.Degree>s2.Degree 263 GROUP BY s1.Sno 264 ORDER BY Degree DESC; 265 266 # 30、查询选修编号为“3-105”且成绩高于选修编号为“3-245”课程的同学的Cno、Sno和Degree。 267 SELECT s1.Cno,s1.Sno,s1.Degree 268 FROM Score s1 269 INNER JOIN Score s2 ON s1.Sno=s2.Sno 270 WHERE s1.Cno='3-105' AND s2.Cno='3-245' AND s1.Degree>s2.Degree 271 272 # 31、查询所有教师和同学的name、sex和birthday. 273 SELECT Sname,Ssex,Sbirthday FROM Student 274 UNION 275 SELECT Tname,Tsex,Tbirthday FROM Teacher; 276 277 # 32、查询所有“女”教师和“女”同学的name、sex和birthday. 278 SELECT Sname,Ssex,Sbirthday 279 FROM Student WHERE sSex='女' 280 UNION 281 SELECT Tname,Tsex,Tbirthday 282 FROM Teacher WHERE tSex='女'; 283 284 # 33、查询成绩比该课程平均成绩低的同学的成绩表。 285 SELECT s1.* 286 FROM Score s1 287 INNER JOIN ( 288 SELECT Cno,AVG(Degree) AS avg_score 289 FROM Score GROUP BY Cno 290 ) AS s2 ON s1.Cno=s2.Cno AND s1.`DEGREE`<s2.avg_score 291 292 293 294 # 34、查询所有任课教师的Tname和Depart. 295 SELECT Tname,Depart 296 FROM Teacher 297 WHERE Tno IN ( 298 SELECT Tno FROM Course GROUP BY Tno 299 ); 300 # 35、查询所有未讲课的教师的Tname和Depart. 301 SELECT Tname,Depart 302 FROM Teacher 303 WHERE Tno NOT IN ( 304 SELECT Tno FROM Course GROUP BY Tno 305 ); 306 307 SELECT Tname,Depart 308 FROM Teacher 309 WHERE NOT EXISTS ( 310 SELECT * FROM Course WHERE Teacher.Tno=Course.Tno 311 ); 312 # 36、查询至少有2名男生的班号。 313 SELECT Class 314 FROM Student 315 WHERE sSex='男' 316 GROUP BY Class 317 HAVING COUNT(*)>1 318 319 # 37、查询Student表中不姓“王”的同学记录。 320 SELECT * 321 FROM Student 322 WHERE sName NOT LIKE '王%'; 323 324 # 38、查询Student表中每个学生的姓名和年龄。 325 SELECT sName AS 姓名,(YEAR(NOW())-YEAR(SBIRTHDAY)) AS 年龄 326 FROM Student 327 328 # 39、查询Student表中最大和最小的Sbirthday日期值。 329 SELECT MIN(Sbirthday) AS 最小日期,MAX(Sbirthday) AS 最大日期 330 FROM Student 331 332 # 40、以班号和年龄从大到小的顺序查询Student表中的全部记录。 333 SELECT * 334 FROM Student 335 ORDER BY Class DESC,(YEAR(NOW())-YEAR(SBIRTHDAY)) DESC 336 337 # 41、查询“男”教师及其所上的课程。 338 SELECT Cno,Cname 339 FROM Course 340 WHERE Tno IN ( 341 SELECT Tno 342 FROM Teacher WHERE Tsex='男' 343 ); 344 345 # 42、查询最高分同学的Sno、Cno和Degree列。 346 SELECT Sno,CNo,Degree 347 FROM Score 348 ORDER BY Degree DESC 349 LIMIT 1; 350 351 # 43、查询和“李军”同性别的所有同学的Sname. 352 SELECT Sname 353 FROM Student 354 WHERE Ssex=( 355 SELECT Ssex 356 FROM Student WHERE SName='李军' 357 ); 358 359 # 44、查询和“李军”同性别并同班的同学Sname. 360 SELECT Sname 361 FROM Student 362 WHERE Ssex=( 363 SELECT Ssex 364 FROM Student WHERE SName='李军' 365 ) AND Class=( 366 SELECT Class 367 FROM Student WHERE SName='李军' 368 ); 369 370 SELECT stu1.SName 371 FROM Student stu1 372 INNER JOIN Student stu2 ON stu2.`SNAME`='李军' 373 WHERE stu1.`SSEX`=stu2.`SSEX` AND stu1.`CLASS`=stu2.`CLASS` 374 375 # 45、查询所有选修“计算机导论”课程的“男”同学的成绩表 376 SELECT * 377 FROM Score 378 WHERE Cno = ( 379 SELECT Cno 380 FROM Course WHERE CName='计算机导论' 381 ) AND Sno IN ( 382 SELECT Sno 383 FROM Student WHERE Ssex='男' 384 );