create table studentsscore(
stu_id varchar2(50) primary key,--学号
kc varchar2(50) not null,--课程)
score decimal(18,1) not null --成绩)
);
insert into studentsscore values('10001','english','23');
insert into studentsscore values('10002','english','46');
insert into studentsscore values('10003','english','76');
insert into studentsscore values('10012','english','83');
insert into studentsscore values('10004','c#','23');
insert into studentsscore values('10005','c#','46');
insert into studentsscore values('10006','c#','73');
insert into studentsscore values('10007','c#','83');
insert into studentsscore values('10008','java','23');
insert into studentsscore values('10009','java','46');
insert into studentsscore values('10010','java','76');
insert into studentsscore values('10011','java','87');
commit;