1、DTD

• student.dtd

  <!-- students元素下只能包含student元素 -->
  <!ELEMENT students (student*)>
  <!-- student元素下必须包含name、age、sex元素 -->
  <!ELEMENT student (name,age,sex)>
  <!--name元素类型为字符串(元素下必须包含字符串)-->
  <!ELEMENT name (#PCDATA)>
  <!--name元素类型为字符串(元素下必须包含字符串)-->
  <!ELEMENT age (#PCDATA)>
  <!--name元素类型为字符串(元素下必须包含字符串)-->
  <!ELEMENT sex (#PCDATA)>
  <!--属性列表，student下包含number属性，ID类型，必需-->
  <!ATTLIST student number ID #REQUIRED>
  

• student.xml 的两个版本
  

  <?xml version="1.0" encoding="utf-8" ?>
  <!DOCTYPE students SYSTEM "student.dtd">
  <students>
    <student number="s001">
        <name>张三</name>
        <age>19</age>
        <sex>男</sex>
    </student>
    <student number="s002">
        <name>李四</name>
        <age>18</age>
        <sex>女</sex>
    </student>
  </students>
  

  <?xml version="1.0" encoding="UTF-8" ?>
  <!DOCTYPE students [
        <!-- students元素下只能包含student元素 -->
        <!ELEMENT students (student*)>
        <!-- student元素下必须包含name、age、sex元素 -->
        <!ELEMENT student (name,age,sex)>
        <!--name元素类型为字符串(元素下必须包含字符串)-->
        <!ELEMENT name (#PCDATA)>
        <!--name元素类型为字符串(元素下必须包含字符串)-->
        <!ELEMENT age (#PCDATA)>
        <!--name元素类型为字符串(元素下必须包含字符串)-->
        <!ELEMENT sex (#PCDATA)>
        <!--属性列表，student下包含number属性，ID类型，必需-->
        <!ATTLIST student number ID #REQUIRED>
        ]>
  <students>
    <student number="s001">
        <name>张三</name>
        <age>18</age>
        <sex>男</sex>
    </student>
  </students>
  

2、Schema

• student.xsd

  <?xml version="1.0" encoding="UTF-8" ?>
  <xsd:schema xmlns="https://www.yusian.com/xml"
            targetNamespace="https://www.yusian.com/xml"
            xmlns:xsd="http://www.w3.org/2001/XMLSchema"
            elementFormDefault="qualified">
    <!--类型定义-->
    <xsd:complexType name="studentsType">
        <xsd:sequence>
            <xsd:element name="student" type="studentType" minOccurs="0" maxOccurs="unbounded"/>
        </xsd:sequence>
    </xsd:complexType>
  
    <!--元素定义-->
    <xsd:element name="students" type="studentsType"/>
  
    <!--类型定义-->
    <xsd:complexType name="studentType">
        <xsd:sequence>
            <xsd:element name="name" type="xsd:string"/>
            <xsd:element name="age" type="ageType"/>
            <xsd:element name="sex" type="sexType"/>
        </xsd:sequence>
        <xsd:attribute name="number" type="numberType" use="required" />
    </xsd:complexType>
  
    <!--类型定义-->
    <xsd:simpleType name="ageType">
        <xsd:restriction base="xsd:integer">
            <xsd:minInclusive value="0"/>
            <xsd:maxInclusive value="255"/>
        </xsd:restriction>
    </xsd:simpleType>
  
    <!--类型定义-->
    <xsd:simpleType name="sexType">
        <xsd:restriction base="xsd:string">
            <xsd:enumeration value="male"/>
            <xsd:enumeration value="female"/>
        </xsd:restriction>
    </xsd:simpleType>
  
    <!--类型定义-->
    <xsd:simpleType name="numberType">
        <xsd:restriction base="xsd:string">
            <xsd:pattern value="s\d{3}"/>
        </xsd:restriction>
    </xsd:simpleType>
  
  </xsd:schema>
  

• student.xml

  <?xml version="1.0" encoding="UTF-8" ?>
  <students xmlns="https://www.yusian.com/xml"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="https://www.yusian.com/xml student.xsd"
  >
    <student number="s001">
        <name>sian</name>
        <age>19</age>
        <sex>male</sex>
    </student>
  </students>