XML is now considered the standard for exchanging data. The rapid growth of XML presents a new set of challenges, particularly to businesses who have historically built their processes around databases. The growth of XML is forcing modern business applications to function with both relational and XML data. XQuery provides a single interface that lets developers access multiple data sources under a unifying data model.
XSLT and XQuery focus on different needs. While there are many tasks that both languages can do well, there are some tasks where one of the languages is far better choice than the other.
The designers of XSLT made the assumption that developers were interested in processing most of the XML document. Therefore XSLT, by default, processes the entire document. They also assumed that developers worked mostly with textual information, so XSLT is not a strongly typed language. Finally XSLT is written as an XML vocabulary.
The designers of XQuery made different assumptions. They assumed that when running a query the developers would want to zoom into a few sections of the document, so they built the language around XPath queries. They also assumed that developers worked with typed data and XQuery is a strongly typed language. Finally, the syntax is more like SQL.
USoft provides support for native Oracle XQuery function using the RDBMS keyword. The examples below demonstrate how.