sql语句，关于怎么建立3个表联系
答案:3 悬赏:30
解决时间 2021-02-14 15:02
- 提问者网友：单纯说谎家
- 2021-02-14 09:53
sql语句，关于怎么建立3个表联系
最佳答案
- 二级知识专家网友：承载所有颓废
- 2021-02-14 11:15
create table CARD(CNO int primary key,NAME varchar2(20),CLASS varchar2(30));
create table BOOKS(BNO int primary key,BNAME varchar2(300),AUTHOR varchar2(20),PRICE NUMBER(8,3),QUANTITY int);
create table BORROW(CNO int,BNO INT,RDATE DATE,FOREIGN KEY (CNO) REFERENCES CARD(CNO),FOREIGN KEY (BNO) REFERENCES BOOKS(BNO));
SELECt CARD.NAME,CARD.CLASS,BORROW.RDATE,CARD.CNO
FROM CARD,BOOKS,BORROW
WHERe CARD.CNO = BORROW.CNO
AND BORROW.BNO = BOOKS.BNO
AND BOOKS.BNAME = '网络';
create table BOOKS(BNO int primary key,BNAME varchar2(300),AUTHOR varchar2(20),PRICE NUMBER(8,3),QUANTITY int);
create table BORROW(CNO int,BNO INT,RDATE DATE,FOREIGN KEY (CNO) REFERENCES CARD(CNO),FOREIGN KEY (BNO) REFERENCES BOOKS(BNO));
SELECt CARD.NAME,CARD.CLASS,BORROW.RDATE,CARD.CNO
FROM CARD,BOOKS,BORROW
WHERe CARD.CNO = BORROW.CNO
AND BORROW.BNO = BOOKS.BNO
AND BOOKS.BNAME = '网络';
全部回答
- 1楼网友：一起来看看吧
- 2021-02-14 12:16
select a1.name,a1.class,a3.rdate,a1.cno
from card a1,books a2,borrow a3
where a1.cno = a3.cno
and a3.bno = a2.bno
and a2.bname = '网络';
- 2楼网友：社会水太深
- 2021-02-14 11:22
create trigger tr_student
on student
for insert
as
begin
if getdate() > convert(date, '2013-05-01')
begin
raiserror("2013年5月1日之后不能插入", 16, 1);
end;
end;
上面的语句， sql 2005 应该是可以的
sql 2000 就不确定了， 你可以测试一下。
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