1 select Sno,Sname from Student where Ssex='女'and Sage>25; 2 --查询选修了“数据库”课程的学生姓名。
3 select Sname from Student where Sno in(select Sno from SC where Cno in(select Cno 4 from Course where Cname='数据库')); 5
6 select Sname from Student,Course,SC Where
7 Student.Sno=SC.Sno and Course.Cno=SC.Cno and Cname='数据库'; 8
9 --统计选修2号课程的人数。
10 select count(*) from Student where Sno in(select Sno from SC where Cno='2'); 11
12 --查询平均成绩大于80分的学生的学号。
13 select Sno,Sname from Student where Sno in
14 (select Sno from SC group by Sno having avg(grade)>80); 15
16 --统计每个系的学生人数。
17 select Count(*)from Student group by Sdept; 18
19 --查询选修数据库课程并且成绩不及格的学生学号和姓名
20 select Student.Sno,Student.Sname 21 from Student,SC,Course 22 where Course.Cname='数据库' and SC.Grade<60 and SC.Cno=Course.Cno and Student.Sno=SC.Sno; 23
24 --自身链接查询
25 --查询每门课程先修课的学分。
26 select first.Cno,second.Ccredit from Course first,Course second 27 where first.Cpno=second.Cno; 28
29 --查询成绩在60到80之间的所有记录。
30 select * from SC where Grade between 60 and 80; 31 --查询成绩为85，86或88的记录
32 select * from SC where Grade='85'or Grade='86' or Grade='88'; 33 -- 查询所有不姓“王”的学生记录。
34 select * from Student where Sname not like '王%'; 35 --以系别和年龄从大到小的顺序查询Student表中的全部记录。
36 select * from Student order by Sdept,Sage Desc; 37 --- 统计男女生分别有多少人。
38 select Ssex,count(*) from Student group by Ssex; 39 -- 查询姓名的第二个字为“小”字的女生信息。
40 select *from Student where Sname like '_小%' and Ssex='女'; 41 select *from Student where Sname like '%小%'; 42 -- 查询成绩最高的三个学生的学号和成绩。
43 select top(3) Sno,SUM(Grade)from SC group by Sno order by SUM(Grade) desc; 44 -- 查询学生的成绩信息，先按学号升序排序，再按成绩降序排序。
45 Select Student.Sno,Student.Sname,Grade from Student,SC 46 where Student.Sno=SC.Sno order by Sno asc, Grade desc; 47
48 --查询至少选修了两门课的学生的学号，选修课程数和选修的平均分数
49 select Sno,COUNT(*),AVG(Grade) from sc group by Sno having count(*)>=2; 50 -- 查询所有比刘晨大的学生的学号，姓名，年龄。
51 select Sno,Sname,Sage from Student where Sage>(select Sage from Student where Sname='刘晨'); 52 -- 求出总分大于150的学生的学号、姓名。
53 select Sno,Sname from Student where sno in( 54 select Sno from SC group by Sno having SUM(Grade)>150); 55
56 select Student.Sno,Student.Sname from Student,SC where
57 Student.Sno=SC.Sno group by SC.Sno,Student.Sno,Student.Sname having sum(Grade)>150
58
59 --实验数据----select SUM(Grade)from SC group by Sno;
60 --列出那些专业相同的学生相应的姓名及专业信息
61 --实验数据----select * from Student group by Sdept having COUNT(*)>=2;
62 select * from Student where Sdept in
63 (select Sdept from Student group by Sdept having COUNT(*)>=2) 64
65 --求至少选修1号课和2号课的学生的学号。
66 select Sno from SC where Sno in (select Sno from SC where Cno=1) and Cno=2; 67
68 --求出所有学生的总成绩 SELECT SUM(成绩) AS 总成绩 FROM 选课
69 select SUM(Grade) as g from SC group by Sno; 70
71 ---列出非电院的所有学生
72 select * from Student where Sdept!='IS'; 73 select * from Student where Sdept<>'IS'; 74 select * from Student where not Sdept='IS'; 75 --列出那些专业相同的学生相应的姓名及专业信息。
76 select a.Sname,b.Sname,a.Sdept 77 from Student a,Student b 78 where a.Sno<>b.Sno and a.Sdept=b.Sdept; 79
80 --、求至少选修1号课和2号课的学生的学号
81 --SELECT X.学号 FROM 选课 X,选课 Y WHERE
82 -- X.学号=Y.学号AND X.课号="1" AND Y.课号="2"
83 select a.Sno from SC a,SC b 84 where a.Sno=b.Sno and a.Cno='1' and b.Cno='2'; 85 --、求选修2号课的学生中，成绩比选修1号课的
86 --最低成绩要高的学生的学号和成绩。
87 select sno,sname from Student where sno in
88 (select Sno from SC where Cno='2' and Grade>( 89 select MIN(Grade)from SC where Cno='1')); 90
91
92 --打开查询分析器用sql语句给u1授予student的查询权限。
93 grant select on Student to u1; 94 -- 把对表SC的查询授予所有用户
95 grant select on SC to public ; 96
97 --给用户u1授予对sc表的查询权限并具有给其他用户授权的权利。
98
99 grant select on SC to u1 with grant option; 100
101 ---让用户u1对用户u2授予对sc表的查询权限。
102
103 grant select on SC to u2; 104
105 --分别回收u2和u1所拥有的权限。
106 revoke all privileges to u2,u1 107 grant select on Student to r1
