Welcome. After reading this thesis I hope you’ll agree with me that XML is the most exciting development on the Internet since Web Application, and that it makes Web site development easier, more productive, and more fun.Since the Internet is an international tool of communication, data transfer and a very efficient market, the companies know that only those who give a useful and fast service will survive. This competition makes the internet user facing a huge quantity of data where the possibility of getting boring if it’s not quiet presented. To solve this issue experts start to think how to present complete internet information and in some time satisfy the end user.The potent combination of the new extensible Markup Language (XML) for portable Internet data exchange, Web applications for portable application logic, and Enterprise relational databases for mission-critical data management is the technology platform of choice for the Internet Applications running the world of multi sources. This project discusses how relational databases and XML fit togetherThe project offers an idea which enables us to gather information coming from various sources and to represent it as one content. It uses the exciting and fast growing world of XML. By doing this project, we’ll be able to achieve proficiency in using XML functionality in .NET Environment as well as develop skills in building XML-database Web Application using ASP.NET.To achieve these goals I have set a main objective is to develop XML-SQL-Oracle-MySQL Web Application. It’s Given an XML document with SQL query and SQL connection string elements as an input parameter to the application. According to theconnection string and the SQL query, the application will connects to the database and run the query. The result from the database will replaces the query string in XML format. Whenever we have the result in XML format we can use it as source of date ready to be stored in other database (SQL Server, Oracle, MySQL...) or delivered to user (Document, Web page ...). By mixing those XML Documents that came from different Database servers and represent it in one XML Document, we are getting the Project Objective.Now our databases can well communicate, this communication environment can’t be done without XML and its large application support. Imagine that we have to organise a large meeting for lots of people from different companies and different cultures. They might all disagree on which items should be on the agenda. They might also disagree on how such meetings should be organised. But we are never going to make any progress on either of these if the participants all speak different languages. Once we agree on a common language, we can concentrate on higher-level things. Here XML is the common language