Ⅰ 用sql语句编程给出创建Student(sno,sname,ssex,sbirthday,sclass)表的完整SQL语句，要求将sno定义为主键，
create table student( sno c(8) prim key, sname c(8), ssex c(2) check ssex='F' or ssex='M' ; default 'F' , sbirthday d , sclass c(10) )
不过你要注意，当用这条语句的时候，应该先建立数据库，把student 作为数据库表，只有数据库表才可以定义主键
Ⅱ 为Student表中的Sno属性升序建立唯一索引,写出相应的SQL语句
create
unique
index
student_sno_idx
on
student(sno);
建立唯一索引的列上不能有重复的值,即该列要满足not
null和unique约束
Ⅲ 第一步，使用SQL语句建立一个表avg_grade，两个字段sno、avggrade，分别为字符串类型和实数类型。
CREATE TABLE AVG_GRADE(SNO VARCHAR(50),AVGGRADE DECIMAL(10,4))
GO
INSERT INTO AVG_GRADE SELECT SNO,AVG(AVGGRADE) FROM SC GROUP BY SNO
GO
CREATE TRIGGER 触发器名 ON SC
FOR INSERT,UPDATE,DELETE
AS
BEGIN
IF EXISTS(SELECT * FROM INSERTED)
BEGIN
DELETE FROM AVG_GRADE WHERE SNO = (SELECT SNO FROM INSERTED)
INSERT INTO AVG_GRADE SELECT SNO,AVG(AVGGRADE) FROM SC WHERE SNO = (SELECT SNO FROM INSERTED) GROUP BY SNO
END
IF EXISTS(SELECT * FROM DELETED) AND NOT EXISTS(SELECT * FROM INSERTED)
BEGIN
DELETE FROM AVG_GRADE WHERE SNO = (SELECT SNO FROM DELETED)
INSERT INTO AVG_GRADE SELECT SNO,AVG(AVGGRADE) FROM SC WHERE SNO = (SELECT SNO FROM DELETED) GROUP BY SNO
END
END
GO
Ⅳ 实验中的SQL部分 学生表:Student(Sno,Sname,Ssex,Sage,Sdept) 课程
1.SELECT * FROM Student;
2.SELECT Sno,Sname,Sage FROM Student WHERE Sdept='信息系';
3.SELECT Sno FROM SC WHERE Grade<60;
5.SELECT * FROM FROM Student ORDER BY Sage ASC;
6.SELECT S.Sno,S.Sname FROM Student S,Course C,SC WHERE S.Sno=SC.Sno AND C.Cno=SC.Cno AND C.Cname=课程名;
7.SELECT Sname,Sage,Sdept FROM Student WHERE Sage BETWEEN 20 AND 23;
8.SELECT S.Sno,S.Sname FROM Student S,Course C,SC WHERE S.Sno=SC.Sno AND C.Cno=SC.Cno AND C.Cname IN ('计算机导论','高等数学');
9.SELECT * FROM Student WHERE Sname LIKE '张%';
11.SELECT COUNT(SC.Sno) FROM Course C,SC WHERE C.Cno=SC.Cno AND Cname=课程名;
12.SELECT S.Sno,S.Sname,SC.Grade FROM Student S,SC WHERE S.Sno=SC.Sno AND SC.Cno='C05' ORDER BY SC.Grade DESC;
13.SELECT Cno,Cname,AVG(Grade),COUNT(Sno) FROM Course C,SC WHERE C.Cno=SC.Cno AND Grade IS NOT NULL GROUP BY Cno,Cname;
15.SELECT Sno,Sname,Sdept FROM Student S,SC WHERE S.Sno=SC.Sno GROUP BY Sno,Sname,Sdept HAVING AVG(Grade)>75;
17.SELECT Sno FROM (SELECT TOP 1 S.Sno,AVG(Grade) FROM Student S,SC WHERE S.Sno=SC.Sno GROUP BY S.Sno ORDER BY AVG(Grade)),
20 SELECT TOP 3 Sno,Sname,Sdept FROM Student S,Course C,SC WHERE S.Sno=SC.Sno AND C.Cno=SC.Cno AND C.Cname='高等数学' ORDER BY SC.Grade;
Ⅳ 用SQL语句在SQL Server2000下实现如下功能。所用数据库表结构如下： student（学生表）：（sno，学号，9字
1.CREATE TABLE SC
(sno varchar(9)，
cno varchar(5)，
grade int )
2.alter table sc add constraint fk_sd_student
foreign key (sno)
references student (sno) on delete cascade
3.select sdept , sname from student where sdept = '计算机系' and ssex = '男'
4.select sno from sc where cno = '200515120'
5.delete from sc where sno in (select sno from student where sdept = '计算机系' and ssex = '男')
6.grant select , update on student to u2
7.select sname from student where sno in
(select sno , count(sno) from sc group by sno
having count(sno) = '总选修课数' )
Ⅵ 写出实现下列操作的SQL语句 （1）建立一个“学生”表Student,它由学号（sno）,
--创建表
createtablestudent
(snochar(8)primarykey,
snamechar(10),
genderchar(2),
departmentchar(20),
ageint)
--修改学号长度
(10)notnull;
--删除表
droptablestudent
Ⅶ 用SQL语句创建简单数据表 设某数据库中有学生表（Students），包括学号sno，姓名snam
create table Students
(
Sno varchar(10) primary key,
Sanme varchar(10) not null,
SD datetime
)
Ⅷ sql中数据库主外键关联问题
你先把student
和
teacher
表建立起来，并且分别把cno和tno设为primarykey.
然后在建立
课程
和
选课
两个表。建立课程表的时候把Tno字段对应上教师表的主键，也就是课程表的Tno字段为教师表主键的外键字段。
同理：成绩表的Sno字段对应学生表的主键，这样两个驻外见关系就建立起来了。
Ⅸ 怎样用SQL命令为表student 以 sno 字段为索引关键字建立主索引
create unique index student_index on student(sno)
Ⅹ 为Student表中的Sno属性升序建立唯一索引，写出相应的SQL语句
create unique index student_sno_idx on student(sno);
建立唯一索引的列上不能有重复的值，即该列要满足not null和unique约束