Querying XML and Relational Data

There has been a growing need for querying heterogeneous data sources, namely XML and Relational databases. Since the relational model is the most data model used to manage data for years. Similarly, the eXtensible Markup Language (XML) is quickly emerging as the de facto standard for data exchange over the Internet. Hence, bridging these two models is surely need. Furthermore, each database system uses a particular query language to manipulate data. So, users need to know each query language of each data model. To this point, we aim to define a system to retrieve data regardless of the nature of the model used and eliminates the burden of learning new languages. In such way, the existing users’ knowledge about a query language will be enough and will meet the purpose. Thus, this paper addresses the problem of accessing both XML and relational data, by using a unique query language expressed with whether SQL or XPath. We rely on a new approach in the translation process to convert the user query into the suitable query language according to the nature of the data interrogated.