Databases and XML offer complementary functionality for storing data. Databases store data for efficient retrieval, whereas XML offers an easy information exchange that enables interoperability between applications. To take advantage of XML's features we can convert database tables into XML documents. We can then use XML tools with such documents for further processing. For example, XML documents can be presented as HTML pages with XSLT style sheets, can be searched with XML-based query languages such as XQL, can be used as a data-exchange format, and so on. The aim of this project is to have a unified database of different underlying databases and integrating heterogeneous databases like SQL database and Oracle database into only one unified database and converting the dataâ„¢s of different relational tables into a standard format like XML. JDBC is used for connecting different databases and integration is done by sequential search of relational tables in the heterogeneous databases. The retrieved query results are converted into XML format. XML parser will parse the XML native code and DTD schema is used for checking the validity of the XML document and the data inside the XML document is displayed in a web browser using CSS style sheet.