SQL练习准备

从简单的SQL开始练习，为了避免自己偷懒，做个记录吧（我一直一直都是很懒的~~）。

需创建的表

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)

);

初始化数据

学生表student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;

教师表teacer数据

insert into teacher values ('t001', '刘阳');

insert into teacher values ('t002', '谌燕');

insert into teacher values ('t003', '胡明星');

commit;

课程表course数据

insert into course values ('c001','J2SE','t002');

insert into course values ('c002','JavaWeb','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;

成绩表sc数据

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');

commit;

有了表和数据，接下来就慢慢按照题目练习了。