15. XML Schema tutorial

XML Schema describes the structure of XML documents.

In this tutorial, you will learn how to read and create the XML Schema language in your application, why XML Schema is more powerful than DTD, and how to use XML Schema in your application.

现在开始学习 XML Schema!

15.1. XML Schema instance

<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="note">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="to" type="xs:string"/>
      <xs:element name="from" type="xs:string"/>
      <xs:element name="heading" type="xs:string"/>
      <xs:element name="body" type="xs:string"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
</xs:schema>

15.2. XML Schema reference manual

In the rookie tutorial, we learn the complete XML Schema elements.

XML Schema reference manual

  • 15.2.1. XML Schema tutorial

    XML Schema describes the structure of XML documents. In this tutorial, you will learn how to read and create the XML Schem...
    2025-10-25 13:35:20 UTC
  • 15.2.2. Introduction to XML Schema

    XML Schema is a XML-based DTD replacement. XML Schema describes the structure of XML documents. The XML Schema language ...
    2025-10-25 13:35:20 UTC
  • 15.2.3. Why use XML Schemas?

    XML Schema is more powerful than DTD. XML Schema supports data types ¶ One of the most important capabilities of XML ...
    2025-10-25 13:35:24 UTC
  • 15.2.4. How do I use XSD?

    XML documents can reference DTD or XML Schema. A simple XML document: ¶ Take a look at this XML document called “note...
    2025-10-25 13:35:23 UTC
  • 15.2.5. XSD-< schema > element

    The < schema > element is the root element of every XML Schema. < schema > element ¶ The < schema > element is the ro...
    2025-10-25 13:35:25 UTC
  • 15.2.6. XSD simple element

    XML Schema defines the elements of the XML file. Simple elements are those that contain only text. It does not contain any...
    2025-10-25 13:35:21 UTC
  • 15.2.7. XSD attribute

    All properties are declared as simple types. What is an attribute? ¶ Simple elements cannot have attributes. If an el...
    2025-10-25 13:35:26 UTC
  • 15.2.8. XSD qualification / Facets

    Restriction is used to define acceptable values for XML elements or attributes. The qualification of the XML element is call...
    2025-10-25 13:35:20 UTC
  • 15.2.9. XSD compound element

    Compound elements contain other elements and / or attributes. What is a compound element? ¶ A compound element is an ...
    2025-10-25 13:35:24 UTC
  • 15.2.10. XSD empty element

    Empty compound elements cannot contain content, only attributes. Compound empty elements: ¶ An empty XML element: ...
    2025-10-25 13:35:25 UTC
  • 15.2.11. XSD contains only elements

    A compound type element that contains only elements is an element that can only contain other elements. Compound types co...
    2025-10-25 13:35:20 UTC
  • 15.2.12. XSD contains text only

    Compound elements that contain only text can contain text and attributes. A compound element that contains only text ¶ ...
    2025-10-25 13:35:27 UTC
  • 15.2.13. XSD mixed content

    Mixed compound types can contain attributes, elements, and text. Composite types with mixed content ¶ The XML element...
    2025-10-25 13:35:23 UTC
  • 15.2.14. XSD indicator

    With indicators, we can control how elements are used in the document. Indicator ¶ There are seven indicators: Orde...
    2025-10-25 13:35:22 UTC
  • 15.2.15. XSD < any > element

    The < any > element gives us the ability to expand XML documents through elements that are not specified by schema! < any...
    2025-10-25 13:35:24 UTC
  • 15.2.16. XSD < anyAttribute > element

    The < anyAttribute > element gives us the ability to extend an XML document with attributes that are not specified by schema...
    2025-10-25 13:35:26 UTC

Principles, Technologies, and Methods of Geographic Information Systems

 102

In recent years, Geographic Information Systems (GIS) have undergone rapid development in both theoretical and practical dimensions. GIS has been widely applied for modeling and decision-making support across various fields such as urban management, regional planning, and environmental remediation, establishing geographic information as a vital component of the information era. The introduction of the “Digital Earth” concept has further accelerated the advancement of GIS, which serves as its technical foundation. Concurrently, scholars have been dedicated to theoretical research in areas like spatial cognition, spatial data uncertainty, and the formalization of spatial relationships. This reflects the dual nature of GIS as both an applied technology and an academic discipline, with the two aspects forming a mutually reinforcing cycle of progress.