Microsoft® SQL Server 2012 Unleashed

Relational Data as XML: The FOR XML Modes

One of the most important uses of XML is to provide a way of describing and encapsulating relational data. Doing so requires a mapping between two basic kinds of data structures: sets and trees. The techniques shown in this section thus have a single goal: converting the columns and rows that make up the sets derived from any SELECT statement into XML trees.

Note that before XML came along, selected result sets would most likely be exported to delimited text files for consumption by disparate systems. Today, most data interchange favors the use of XML. In response, developers have come to rely on XSL for Transformations (XSLT) as a companion skill for translating XML into HTML, PDF, RTF, or any other ...