oracle创建表(约束)

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图书信息表：图书编号，图书名称，出版社，出版日期，图书价格，图书作者，借出标识，读者编号，描述
①主键 constraint pk_name primary key <column_name>
②外键 constraint fk_name foreign key(column_name) reference table_name(column_name)
③检查 constraint ck_name check (condition)
④唯一 constraint un_name unique (column_name)
⑤非空 <column name> <data type> not null,
⑥默认值<column name> <data type> default <default value>,

--没有任何约束条件create table bookinfo{bookid int,bookname char,publish varchar2(20),pubdata varchar2(20),price decimal,author char(40),store int,reader int,remarks varchar2(50)};--指定了默认值：price storecreate table bookinfo{bookid int,bookname char,publish varchar2(20),pubdata varchar2(20),price decimal(7,2) default 0.0,author char(40),store int default 0 not null,reader int,remarks varchar2(50)};--检查约束：pricecreate table bookinfo{bookid int,bookname char,publish varchar2(20),pubdata varchar2(20),price decimal,author char,store int,reader int,remarks varchar2(50),constraint ck_price check (price>=10 and price<=100)};--非空约束:bookid booknamecreate table bookinfo{bookid int not null,bookname char not null,publish varchar2(20),pubdata varchar2(20),price decimal,author char,store int,reader int,remarks varchar2(50)};--唯一约束：booknamecreate table bookinfo{bookid int,bookname char,publish varchar2(20),pubdata varchar2(20),price decimal,author char,store int,reader int,remarks varchar2(50),constraint un_bookname unique(bookname)};--外键约束 publishcreate table publishinfo{publishid varchar2(20) primary key,publishname varchar(30)}create table bookinfo{bookid int,bookname char;publish varchar2(20),pubdata varchar2(20),price decimal,author char,store int,reader int,remarks varchar2(50),constraint fk_publish foreign key (publish) references publishinfo(publishid)};--创建一个含有多个约束的表create table bookinfo{bookid int,bookname char,publish varchar2(20) not null,pubdata varchar2(20),price decimal,author char,store int,reader int,remarks varchar2(50),constraint ck_price check (price<=100),constraint un_bookname unique (bookname)};

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