In Chapter 4, Development with SharePoint Designer 2010, we explored the use of the XSLT List View Web Part, a very specialized and powerful Web Part for use with SharePoint lists and libraries. At the base of this Web Part is the Data Form Web Part. This more fundamental Web Part can still easily make use of SharePoint's List and Library data, but it can also make direct use of external data connections to relational databases, REST Services, web services, or even plain old XML files.
In this recipe, we will use two connected Data Form Web Parts. One will display the list of publishers directly from the pubs database, and the second connected list will show the books (publications) from the selected publisher.