Using XML Schema Built-in Datatypes Incorrectly

This section describes a tutorial example of using built-in datatypes incorrectly.

The namespace rule on built-in datatypes is very important. If you don't follow it, you will get errors we shown in the following schema examples, holiday_error.xsd:

<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
   xmlns:xsd="http://www.w3.org/2001/XMLSchema-datatypes">

<!-- holiday_error.xsd
 - Copyright (c) 2002-2013 HerongYang.com. All Rights Reserved.
-->

 <!-- Examples of incorrect built-in datatype "date" -->
 <xs:element name="holiday1" type="date"/>

 <xs:element name="holiday2" type="w3c:date"/>

 <xs:element name="holiday3" type="xsd:date"/>

</xs:schema>

Here is the output of XsdSchemaChecker.java on this schema:

herong> java XsdSchemaChecker holiday_error.xsd
Error:
   Line number: 10
   Column number: 43
   Message: src-resolve: Cannot resolve the name 'date' to a(n)
   'type definition' component.

Error:
   Line number: 12
   Column number: 47
   Message: s4s-att-invalid-value: Invalid attribute value for
   'type' in element 'element'. Recorded reason: UndeclaredPrefix:
   Cannot resolve 'w3c:date' as a QName: the prefix 'w3c' is not
   declared.

Error:
   Line number: 14
   Column number: 47
   Message: src-resolve.4.2: Error resolving component 'xsd:date'.
   It was detected that 'xsd:date' is in namespace
   'http://www.w3.org/2001/XMLSchema-datatypes', but components
   from this namespace are not referenceable from schema document
   'file:/C:/herong/holiday_error.xsd'. If this is the incorrect
   namespace, perhaps the prefix of 'xsd:date' needs to be changed.
   If this is the correct namespace, then an appropriate 'import'
   tag should be added to 'file:/C:/herong/holiday_error.xsd'.

Error:
   Line number: 14
   Column number: 47
   Message: src-resolve: Cannot resolve the name 'xsd:date' to a(n)
   'type definition' component.

Schema File: holiday_error.xsd
Parser Class: com.sun.org.apache.xerces.internal.jaxp.validation.SimpleXMLSchema

The error messages are pretty clear.

Table of Contents

 About This Book

 Introduction to XML Schema

 XML Editor and Schema Processor - XMLPad

 Java API for XML Processing - JAXP

 JAXP - XML Schema (XSD) Validation

 Xerces2 Java Parser - Java API of XML Parsers

 Using Xerces2 Java APIs

XML Schema Language - Basics

 Schema and Schema XML Representation

 Checking Schema Documents - XsdSchemaChecker.java

 Creating Schema Documents - "schema" Element

 Declaring Root Elements - "element" Element

 Specifying Element Datatype - "type" Attribute

 Using XML Schema Built-in Datatypes

Using XML Schema Built-in Datatypes Incorrectly

 Validating XML Documents against Schema Documents

 Deriving New Simple Datatypes - "simpleType" Element

 Defining Complex Datatypes - "complexType" Element

 Validation Error Examples on Complex Datatypes

 Introduction of XSD Built-in Datatypes

 "string" and Its Derived Datatypes

 "decimal" and Its Derived Datatypes

 "dateTime" and Its Related Datatypes

 Miscellaneous Built-in Datatypes

 Facets, Constraining Facets and Restriction Datatypes

 "simpleType" - Defining Your Own Simple Datatypes

 Complex Element Declaration

 Identity-Constraints: unique, key and keyref

 Assertion as Custom Validation Rules

 XML Schema Location and Namespace in XML Documents

 Overriding Element Types in XML Documents

 Linking Multiple Schema Documents Together

 Glossary

 Archived Tutorials

 References

 Full Version in PDF/EPUB