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Vector Data Language

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2 Feb 2004 1  
This article covers the Vector Data Language, an XML-based language to manipulate XML data from ODBC sources.

Introduction

Data Access is one of the most predominant aspects of any development project. Providing a reliable and trusted means of accessing data across disparate data sources becomes highly prized to many developers, especially as they have to develop their own Data Access Frameworks (DAF), or use one of the many DAFs available on the Internet.

Vector Data Language aims to be the solution to the data access problems encountered by both businesses and developers alike.

Background

Data Access Frameworks generally come fully equipped with database analyzers which look at either your stored procedures or the command that you wish to execute (e.g. SELECT * FROM Customers) and then build code that you can use in your application.

However, none of these DAFs are true frameworks, as they build components for use inside existing applications. Most, if not all, only connect to a single Data Provider such as Microsoft SQL Server or Oracle, and when your data back-end changes, you have to re-build all of your DACs. In some very extreme cases, when the Data Provider changes from say Microsoft SQL Server to an Oracle solution, developers have to re-develop their DAF for compatibility with the new Data Provider.

What

Vector Data Language (VectorDL) is an XML-based data access/manipulation language. It has the ability to connect to any ODBC compliant Data Source and to present the results in XML. Using XSL transformation technology, the XML result can be formatted into any other XML compliant format such as XHTML or even another format of XML. This is particularly useful when providing data directly to Information Partners, where they don't need to see the raw XML data, but rather a formatted XHTML report.

VectorDL does not build any components to be used in client side applications. The XML result can be processed by the client application using XSL and XPath technologies. Using this approach, developers no longer have to worry about the actual structure of the Data Source. If the back-end requirements of the database changes, VectorDL still provides the same reliable XML, and if the structure of the actual data changes, VectorDL's transformation engine (Shift) can transform the document into the correct format for use by the client-side application.

VectorDL also allows developers for the first time to call related data from multiple ODBC Data Sources within a single procedure, or to update information across disparate systems. No other Data Access Framework allows this type of functionality, before VectorDL developers had to write code to handle queries and updates across disparate systems.

How

VectorDL achieves all this by using an ODBC compliant query engine that returns all data in XML. By hosting VectorDL inside a Web Service (Vector), it is accessible from any client, no matter what means they use to access the Web Service or what Operating System they are using.

Using the XSL transformation engine, Vector can provide XHTML reports on data. This means that when a customer visits your website (that implements Vector), he views a report (or a data entry/edit form) which allows him to interact with your data in a user friendly environment.

However, when an application accesses Vector, the application views raw XML and uses XPath to navigate through the data.

Why

Businesses want applications to be as dynamic as business itself. An application that uses hard-coded methods to access and manipulate data will quickly become obsolete, imploring constant development on the application, and a constant supply of possible errors. Data can become corrupt when fresh compiled applications try to access them.

Working with Data Access Frameworks, the number of possible errors are reduced as the framework provides the required consistency, but still need applications to be recompiled to use the new and updated components.

VectorDL provides the means for businesses to develop an application with a shelf life of more than 3 weeks (the length of an Internet year). Always providing the same consistent XML data via the Web Service interface means that developers no longer have to worry about the structure of the data or where to connect to get to the data.

When the data structure changes, simple XSL transformations can be done on the data to format the data into the required format for the hard-coded application to use. This means that developers only hard-code the XPath information to access the required data within the XML document, and from the outside of the compiled application (using VectorDL's transformation library, Shift) they reformat data from the Data Providers into the required format.

Where

VectorDL is hosted in a Web Service, providing access to any system that can call a Web Service. Distributed applications can call a VectorDL script from anywhere in the world. Providing data access has never been so easy.

Businesses can host the Web Service and include XSL transformations to transform the XML into XHTML pages which can be hosted on their website, allowing a dynamic data driven website to their customers and suppliers.

When

Many companies still find that living in yesterday's world today is a good idea when it comes to data sharing and exchange between Information Partners. VectorDL will enable you to use today's technology standards today, with an eye on tomorrow.

License

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