Merge XML Documents

摘要

ML is becoming an increasingly common data store. One of XML's advantages is that you can work with your data as discrete files that might come from different sources. You might also want to merge XML files to create reports, store the output in a database, or display it in a user interface. I'll show you how to do an intimate merge between discrete XML data files. I call it an intimate merge because it not only adds new elements, but it updates individual elements' attributes as well. Along the way, you'll get a better understanding of the role of XML Schema Definition (XSD) schemas, how to validate an XMLDocument object as you load it, and the role of recursion in processing XML data. You might use this merging process in the real world by taking data from several external sources, such as a database, output from an accounting package such as QuickBooks, and the results of a Web-based survey (see Figure 1). I'll simplify the example to use data from the Customers and Orders tables from the SQL Server sample Northwind database and merge it with a file that mimics the result of a Web-based satisfaction survey. You can extend the approach to whatever data you work with.