Until now, schemas have been a missing piece of the XML puzzle for Enterprise Application Integration (EAI). In this article, B2B expert Andre Yee discusses the emerging XML Schema for EAI.

The DataSet class makes it very easy to load XML data into an instance of the class, and then work with it as relational data. However, many questions arise when developers start loading nested XML elements into a data set. That's when a little understanding of what's going on under the covers goes a long way toward obtaining the results you expect.

The XML Schema definition language (XSD) enables you to define the structure (elements and attributes) and data types for XML documents. It enables this in a way that conforms to the relevant W3C recommendations for XML schema. XSD is just one of several XML schema definition languages but is the one best supported by Microsoft in .NET.

This article, written by Priscilla Walmsley, a member of the W3C working group that created XML Schema, provides a high-level overview of W3C XML Schema. It describes the basic features of XML Schemas and provides specific examples of its functionality.

This technology preview implements the core feature set of the XML DCD submission while using the element names of XML Data. While the two notes are similar in structure, there is some difference in keywords and the like. Note that the inheritance and subclassing features described in an appendix of the DCD note are not included in the preview implementation. Generally speaking, XML Schema loses relations, aliases, inheritance, and complex types as defined in XML Data.

A recent article on devx.com discusses the use of xs:all to constrain a mixed content model groups. The question posed in the article perked my ears because I thought it was obvious that xs:all was not appropriate to the problem.

XML namespaces provide a mechanism for creating a unique means of identifying components that might have similar names, but different structures. In this article, David Gulbransen describes how namespaces are used.

Sometimes DTDs don't offer the functionality you need for your XML documents, and sometimes a DTD that's already in place needs to be converted to an XML Schema. In this article, David Gulbransen walks through the conversion process from DTD to XML Schema.

XML Schemas may not be right for every application. In this article, David Gulbransen describes situations in which RELAX NG or Schematron may be a better choice as a schema, or how they could supplement XML Schemas.

This article, by Graeme Malcolm, will show how to retrieve data using XML Schemas and SQLXML functionality. Beginning with a discussion of schemas and the XSD syntax, default and explicit mappings will be described. Graeme will then introduce the relationship annotation and its use in retrieving data from multiple, related tables. The key-fields annotation is discussed next, followed by the use of the is-constant annotation.

The primary building block for conveying meaningful information with XML is the W3C's XML Schema language. This article shows you step by step how to beat XML Schema into submission.

Some programming languages, such as Perl, include a regular expression language, which defines a pattern against which a series of characters can be compared. Typically, this feature is used to search for fragments of a text document, but the XML Schema language has co-opted it for sophisticated validation of element content and attribute values. Neil Bradley explains.

Go beyond Visual Studio’s graphical tools to bring increased power and flexibility to your data layer. Learn how to modify your XML Schema and live in peace with your DBA.

Learn the difference between typed datasets and classes generated by the xsd.exe tool, as well as how to extend this code generation process by reusing the infrastructure classes supporting it, while remaining compatible with the XmlSerializer.

The new XML Schema system, now nearing acceptance as a W3C recommendation, aims to provide a rich grammatical structure for XML documents that overcomes the limitations of the DTD (see the sidebar, Limitations of DTDs). This article demonstrates the flexibility of schemas and shows how to define the most fundamental building block of XML documents -- the element -- in the XML Schema system.

Start using XML Schema to constrain XML documents. This brief tip tells how to reference an XML schema from your XML documents. Five pieces of sample code show how.

This tip explains how the XML Schema specification requires one XML Schema per namespace, and shows you how to include more than one schema for a document and how to reference one schema from another.

In the April 2002 issue I covered the basics of XML Schema, including how you define elements, attributes, complex types, and how to use the built-in data types. In this month's column I'll introduce the more powerful features of the language, which are related to defining custom types and type hierarchies.

Of all the XML technologies, XML Schema is most valuable to software developers because it finally makes it possible to add type information to XML documents. This column is the first in a two-part series that will cover the basics of XML Schema.

A counterpoint to Kohsuke Kawaguchi's article on guidelines for working with W3C XML Schema that revisits each of his original guidelines and offers agreement, disagreement, or clarification of each major point. Provides additional guidelines for what you should and should not do when working with W3C XML Schema.