Heim >Datenbank >MySQL-Tutorial >学生表sid,sname,成绩表cid,cname,学生成绩表sid,cid,cscore,要
学生表sid,sname,成绩表cid,cname,学生成绩表sid,cid,cscore,要
- WBOYOriginal
- 2016-06-07 16:01:012171Durchsuche
--1、建表SQL: --学生表： -- Createtable createtable STUDENT ( SID NUMBERnotnull, SNAME NVARCHAR2(40) ) tablespace CABLESCD pctfree10 initrans1 maxtrans255 storage ( initial64 minextents1 maxextentsunlimited ); --成绩表 -- Createtable creat
--1、建表SQL:
--学生表：
-- Createtable
createtable STUDENT
(
SID NUMBERnotnull,
SNAME NVARCHAR2(40)
)
tablespace CABLESCD
pctfree10
initrans1
maxtrans255
storage
(
initial64
minextents1
maxextentsunlimited
);
--成绩表
-- Createtable
createtable SCORE
(
CID NUMBERnotnull,
CNAME NVARCHAR2(40) notnull
)
tablespace CABLESCD
pctfree10
initrans1
maxtrans255
storage
(
initial64
minextents1
maxextentsunlimited
);
--学生成绩表
-- Createtable
createtableSTUDENGSCORE
(
SID NUMBERnotnull,
CID NUMBERnotnull,
CSCORE NUMBER(4,2)
)
tablespace CABLESCD
pctfree10
initrans1
maxtrans255
storage
(
initial64
minextents1
maxextentsunlimited
);
--2、插入SQL语句：
insert into student
(sid, sname)
values
(001,'ZHAOHY');
insert into student
(sid, sname)
values
(002, 'ZHANGQL');
insert into student
(sid, sname)
values
(003, 'ZHAOHB');
insert into score
(cid, cname)
values
(100, '数电');
insert into score
(cid, cname)
values
(200, '模电');
insert into score
(cid, cname)
values
(300, '英语');
insert into score
(cid, cname)
values
(400, '政治');
select * from score
(001, 100, '60');
insert into studengscore
(sid, cid, cscore)
values
(002, 100, '70');
insert into studengscore
(sid, cid, cscore)
values
(003, 100, '80');
insert into studengscore
(sid, cid, cscore)
values
(003, 200, '90');
insert into studengscore
(sid, cid, cscore)
values
(003, 300, '99');
insert into studengscore
(sid, cid, cscore)
values
(003, 400, '98');
select * from studengscore
--3、查询SQL
select * fromstudengscore;
select * from student;
select * from score;
select cnamefrom score where cid =(select cid fromstudengscore wherecscore=(
selectmax(cscore) fromstudengscore where sid=3 ));
