基本查询:
1、 查询Student表中的所有记录的Sname、Ssex和Class列。 Select sname,ssex,class from student 2、 查询教师所有的单位即不重复的Depart列。 Select distinct depart from teacher 3、 查询Student表的所有记录。 Select * from student 4、 查询Score表中成绩在60到80之间的所有记录。 Select * from score where degree between 60 and 80 5、 查询Score表中成绩为85,86或88的记录。 (1) Seclet * from score where degree=85 or degree=86 or degree=88; (2) Select * from score where degree in(85,86,88) 6、 查询Student表中“95031”班或性别为“女”的同学记录。 Select * from student where class=95031 and ssex=’女’; 7、 以Class降序查询Student表的所有记录。 Select * from student order by class desc; 8、以Cno升序、Degree降序查询Score表的所有记录。 Select * from score order by cno asc,degree desc; 9、查询“95031”班的学生人数。 Select * from student where class=95031; 10、查询Score表中的最高分的学生学号和课程号。(子查询或者排序) Select * from score where degree=(select max(degree) from score); 11、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。 select avg(degree) from score group by cno; 12、查询每门课的平均成绩。 select avg(degree) from score group by cno; 13、查询分数大于70,小于90的Sno列。 Select sno from score where degree between 70 and 90; 14、查询所有学生的Sname、Cno和Degree列。 Select student.sname,score.cno,score.degree from student,score where sno=son; 15、查询所有学生的Sno、Cname和Degree列。 select student.sno,course.cname,score.degree from student join course join score on student.sno=score.sno and score.cno=course.cno; 16、查询所有学生的Sname、Cname和Degree列。 Select student.sname,course.cname,score.degree from student,course,score where sno=son; 17、 查询“95033”班学生的平均分 select avg(degree) from score join student on student.class='95033' and student.sno=score.sno; 18、 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。 select * from score where cno='3-105' and degree>(select degree from score where sno='109' and cno='3-105'); 20、查询score中选学多门课程的同学中分数为非最高分成绩的记录。 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。 select * from score where cno='3-105' and degree>(select degree from score where sno='109' and cno='3-105'); 22、查询和学号为107的同学同年出生的所有学生的Sno、Sname和Sbirthday列。 select * from student where sno <> '107' and year(sbirthday) = (select year(sbirthday) from student where sno = '107'); 23、查询“张旭“教师任课的学生成绩(姓名)。 select sname,degree from teacher join score join course join student on teacher.tno = course.tno and score.cno=course.cno and score.sno=student.sno where teacher.tname='张旭'; 查询考计算机导论的学生成绩 select degree from score join course on course.cno=score.cno and score.cno='3-105'; 查询李诚老师教的课程名称 select cname from course join teacher on course.tno = teacher.tno and teacher.tname='李诚'; 教高等数学的老师是哪个系的 select depart from teacher join course on teacher.tno = course.tno and course.cname='高等数学'; 24、查询选修某课程的同学人数多于5人的教师姓名。 25、查询95033班和95031班全体学生的记录。 select * from student where class='95033' or class='95031'; 26、 查询存在有85分以上成绩的课程Cno. select cno from score where degree>85; 27、查询出“计算机系“教师所教课程的成绩表。 select degree from course join score on course.cno='3-105' and score.cno='3-105'; 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。 select * from score where cno='3-105' and degree>(select min(degree) from score where cno='3-245') order by degree desc; 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. select * from score where cno='3-105' and degree>(select max(degree) from score where cno='3-245'); 31、 查询所有教师和同学的name、sex和birthday. select tname,tsex,tbirthday from teacher union select sname,ssex,sbirthday from student; 32、查询所有“女”教师和“女”同学的name、sex和birthday. select tname,tsex,tbirthday from teacher where tsex='女' union select sname,ssex,sbirthday from student where ssex='女'; 33、 查询成绩比该课程平均成绩低的同学的成绩表。 select * from 34、 查询所有任课教师的Tname和Depart. select tname,depart from teacher; 35、查询所有未讲课的教师的Tname和Depart. select tname,depart from teacher where prof='助教'; 36、查询至少有2名男生的班号。 select class from student where ssex='男' group by class having count(*)>1; 37、查询Student表中不姓“王”的同学记录。 select * from student where not sname like '%王%'; 38、查询Student表中每个学生的姓名和年龄。 39、查询Student表中最大和最小的Sbirthday日期值。 select min(sbirthday) max,max(sbirthday) min from student; 40、以班号和年龄从大到小的顺序查询Student表中的全部记录。 41、查询“男”教师及其所上的课程。 select teacher.tsex,course.cname from teacher join course on teacher.tsex='男' and teacher.tno=course.tno; 42、查询最高分同学的Sno、Cno和Degree列。 select * from score where degree=(select max(degree) from score); 43、查询和“李军”同性别的所有同学的Sname. select sname from student where ssex='男'; 44、查询和“李军”同性别并同班的同学Sname. select sname from student where ssex='男' and class='95033'; 45、查询所有选修“计算机导论”课程的“男”同学的成绩表。 select degree from
1.union 合并两个或者多个select语句