Chapter 1: Schemas: an introduction

Full example

This example consists of a very simple instance and schema.

Instance (chapter01.xml)

<product effDate="2001-04-02"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="chapter01.xsd">
  <number>557</number>
  <size>10</size>
</product>

Schema (chapter01.xsd)

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="product" type="ProductType"/>
  <xs:complexType name="ProductType">
    <xs:sequence>
      <xs:element name="number" type="xs:integer"/>
      <xs:element name="size" type="SizeType"/>
    </xs:sequence>
    <xs:attribute name="effDate" type="xs:date"/>
  </xs:complexType>
  <xs:simpleType name="SizeType">
    <xs:restriction base="xs:integer">
      <xs:minInclusive value="2"/>
      <xs:maxInclusive value="18"/>
    </xs:restriction>
  </xs:simpleType>
</xs:schema>

Book examples

Example 1-1. Product instance

<product effDate="2001-04-12">
  <number>557</number>
  <size>10</size>
</product>

Example 1-2. Product schema in XSD schema language

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="product" type="ProductType"/>
  <xs:complexType name="ProductType">
    <xs:sequence>
      <xs:element name="number" type="xs:integer"/>
      <xs:element name="size" type="SizeType"/>
    </xs:sequence>
    <xs:attribute name="effDate" type="xs:date"/>
  </xs:complexType>
  <xs:simpleType name="SizeType">
    <xs:restriction base="xs:integer">
      <xs:minInclusive value="2"/>
      <xs:maxInclusive value="18"/>
    </xs:restriction>
  </xs:simpleType>
</xs:schema>

Example 1-3. Product schema in DTD schema language

<!ELEMENT product (number, size?)>
<!ELEMENT number (#PCDATA)>
<!ELEMENT size (#PCDATA)>
<!ATTLIST product effDate CDATA #IMPLIED>