XML and SQL: Developing Web Applications

Let SQL Server Do the Work

Our workhorse here is the good, old FOR XML clause, but we're going to use it in an unorthodox, but perfectly legal, fashion. The FOR XML clause takes some optional arguments after the mode argument (RAW, AUTO, or EXPLICIT) discussed earlier in the chapter. You can add the argument XMLDATA after the mode argument, and SQL Server will return some additional information along with your XML data set. This argument tells SQL Server to return not only the result set formatted in XML, but also an XDR schema that defines the structure of XML data returned. How convenient!

Executing a query that returns fields of the tables that you want in your XDR schema is one way to get a good start on building an XDR schema for your XML ...