Applied XML Programming for Microsoft® .NET

Reading XML Data from Databases

With SQL Server 2000, you have two basic ways to retrieve data as XML: you can use the XML extensions to the SELECT command, or you can execute a query on a particular text or BLOB field that is known to contain XML data. SQL Server does not mark these fields with a special attribute or data type to indicate that they contain XML data, however.

With the first technique, you typically use the FOR XML clause in a traditional query command. In response, the DBMS executes the query in two steps. First it executes the SELECT statement, and next it applies the FOR XML transformation to a rowset. The resulting XML is then sent to the client as a one-column­ rowset.

Note

Although specific to the OLE DB specification, ...