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create table student(  
sno varchar2(10) primary key,  
sname varchar2(20),  
sage number(2),  
ssex varchar2(5)  
);  
create table teacher(  
tno varchar2(10) primary key,  
tname varchar2(20)  
);  
create table course(  
cno varchar2(10),  
cname varchar2(20),  
tno varchar2(20),  
constraint pk_course primary key (cno,tno)  
);  
create table sc(  
sno varchar2(10),  
cno varchar2(10),  
score number(4,2),  
constraint pk_sc primary key (sno,cno)  
);  
/*******初始化学生表的数据******/  
insert into student values ('s001','张三',23,'男');  
insert into student values ('s002','李四',23,'男');  
insert into student values ('s003','吴鹏',25,'男');  
insert into student values ('s004','琴沁',20,'女');  
insert into student values ('s005','王丽',20,'女');  
insert into student values ('s006','李波',21,'男');  
insert into student values ('s007','刘玉',21,'男');  
insert into student values ('s008','萧蓉',21,'女');  
insert into student values ('s009','陈萧晓',23,'女');  
insert into student values ('s010','陈美',22,'女');  
commit;  
#/******************初始化教师表***********************/  
insert into teacher values ('t001', '刘阳');  
insert into teacher values ('t002', '谌燕');  
insert into teacher values ('t003', '胡明星');  
commit;  
/***************初始化课程表****************************/  
insert into course values ('c001','J2SE','t002');  
insert into course values ('c002','Java Web','t002');  
insert into course values ('c003','SSH','t001');  
insert into course values ('c004','Oracle','t001');  
insert into course values ('c005','SQL SERVER 2005','t003');  
insert into course values ('c006','C#','t003');  
insert into course values ('c007','JavaScript','t002');  
insert into course values ('c008','DIV+CSS','t001');  
insert into course values ('c009','PHP','t003');  
insert into course values ('c010','EJB3.0','t002');  
commit;  
/***************初始化成绩表***********************/  
insert into sc values ('s001','c001',78.9);  
insert into sc values ('s002','c001',80.9);  
insert into sc values ('s003','c001',81.9);  
insert into sc values ('s004','c001',60.9);  
insert into sc values ('s001','c002',82.9);  
insert into sc values ('s002','c002',72.9);  
insert into sc values ('s003','c002',81.9);  
insert into sc values ('s001','c003',59);