<!ATTLIST 元素名称 属性名称 数据类型 附加条件>
TIP:声明元素的时候,元素的数据类型是PCDATA
属性的时候,实行的数据类型是CDATA
@H_404_19@
dtd的代码:
<?xml version="1.0" encoding="UTF-8"?> <!ELEMENT movies (movie+)> <!ELEMENT movie (title,actor,rating)> <!ELEMENT title (#PCDATA)> <!ELEMENT actor (#PCDATA)> <!ELEMENT rating (#PCDATA)> <!ATTLIST movie id CDATA #required> <!ATTLIST movie type CDATA #IMPLIED>@H_404_19@ 对应xml代码:
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE movies SYSTEM "demo9.dtd"> <movies> <movie id="1" type=""> <title/> <actor/> <rating/> </movie> <movie id="1"> <title/> <actor/> <rating/> </movie> </movies>@H_404_19@ @H_404_19@
@H_404_32@
含义
语法
必填属性
#IMPLIED
属性可有可无
default
默认值
FIXED
固定值
枚举
枚举
ID
唯一
例题:写出下面xml的dtd文件
dtd代码:
<?xml version="1.0" encoding="UTF-8"?> <!ELEMENT books (book+)> <!ELEMENT book (#PCDATA)> <!ATTLIST book id ID #required> <!ATTLIST book medium CDATA #FIXED '纸质'> <!ATTLIST book type CDATA '计算机'> <!ATTLIST book pub (北京大学出版社|工业出版社|邮电出版社) "北京大学出版社"> <!ATTLIST book pagesize CDATA #IMPLIED>@H_404_19@ 对应的xml代码:
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE books SYSTEM "demo10.dtd"> <books> <book id="s001" medium="纸质" type="计算机" pub="北京大学出版社" pagesize="300"> </book> </books>