Table of contents

Appendices

5 Advanced Concepts III: The Quarterly Report

The home-products ordering and billing application can generate ad-hoc reports that summarize how many of which types of products have been billed on a per region basis. An example of such a report, one that covers the fourth quarter of 1999, is shown in 4Q99.xml.

Notice that in this section we use qualified elements in the schema, and default namespaces where possible in the instances.

NOTE: 

Quarterly Report, 4Q99.xml

<purchaseReport
  xmlns="http://www.example.com/Report"
  period="P3M" periodEnding="1999-12-31">

  <regions>
    <zip code="95819">
      <part number="872-AA" quantity="1"/>
      <part number="926-AA" quantity="1"/>
      <part number="833-AA" quantity="1"/>
      <part number="455-BX" quantity="1"/>
    </zip>
    <zip code="63143">
      <part number="455-BX" quantity="4"/>
    </zip>
  </regions>

  <parts>
    <part number="872-AA">Lawnmower</part>
    <part number="926-AA">Baby Monitor</part>
    <part number="833-AA">Lapis Necklace</part>
    <part number="455-BX">Sturdy Shelves</part>
  </parts>

</purchaseReport>

The report lists, by number and quantity, the parts billed to various zip codes, and it provides a description of each part mentioned. In summarizing the billing data, the intention of the report is clear and the data is unambiguous because a number of constraints are in effect. For example, each zip code appears only once (uniqueness constraint). Similarly, the description of every billed part appears only once although parts may be billed to several zip codes (referential constraint), see for example part number 455-BX. In the following sections, we'll see how to specify these constraints using XML Schema.

NOTE: 

The Report Schema, report.xsd

<schema targetNamespace="http://www.example.com/Report"
        xmlns="http://www.w3.org/2001/XMLSchema"
        xmlns:r="http://www.example.com/Report"
        xmlns:xipo="http://www.example.com/IPO"
        elementFormDefault="qualified">

  <!-- for SKU -->
  <import namespace="http://www.example.com/IPO"/>

  <annotation>
    <documentation xml:lang="en">
      Report schema for Example.com
      Copyright 2000 Example.com. All rights reserved.
    </documentation>
  </annotation>

  <element name="purchaseReport">
    <complexType>
      <sequence>
        <element name="regions" type="r:RegionsType"/>
          <keyref name="dummy2" refer="r:pNumKey">
            <selector xpath="r:zip/r:part"/>
            <field xpath="@number"/>
          </keyref>
        </element>
        <element name="parts" type="r:PartsType"/>
      </sequence>
      <attribute name="period"       type="duration"/>
      <attribute name="periodEnding" type="date"/>
    </complexType>

    <unique name="dummy1">
      <selector xpath="r:regions/r:zip"/>
      <field xpath="@code"/>
    </unique>

    <key name="pNumKey">
      <selector xpath="r:parts/r:part"/>
      <field xpath="@number"/>
    </key>

    <keyref name="dummy2" refer="r:pNumKey">
      <selector xpath="r:regions/r:zip/r:part"/>
      <field xpath="@number"/>
    </keyref>

  </element>

  <complexType name="RegionsType">
    <sequence>
      <element name="zip" maxOccurs="unbounded">
        <complexType>
          <sequence>
            <element name="part" maxOccurs="unbounded">
              <complexType>
                <complexContent>
                  <restriction base="anyType">
                    <attribute name="number"   type="xipo:SKU"/>
                    <attribute name="quantity" type="positiveInteger"/>
                  </restriction>
                </complexContent>
              </complexType>
            </element>
          </sequence>
          <attribute name="code" type="positiveInteger"/>
        </complexType>
      </element>
    </sequence>
  </complexType>

  <complexType name="PartsType">
    <sequence>
      <element name="part" maxOccurs="unbounded">
        <complexType>
          <simpleContent>
            <extension base="string">
              <attribute name="number" type="xipo:SKU"/>
            </extension>
          </simpleContent>
        </complexType>
      </element>
    </sequence>
  </complexType>

</schema>