You can delete a document by calling XmlContainer::deleteDocument(). This method can operate either on a document's name or on an XmlDocument object. You might want to use an XmlDocument object to delete a document if you have queried your container for some documents and you want to delete every document in the results set.

For example:

#include "DbXml.hpp"
...

using namespace DbXml;

...

// Get a manager object.
XmlManager myManager;

// Open a container
XmlContainer myContainer = 
    myManager.openContainer("exampleData.dbxml");

// Get a query context
XmlQueryContext context = myManager.createQueryContext();
// Declare a namespace
context.setNamespace("fruits", "http://groceryItem.dbxml/fruits");

// Declare the query string. Find all the product documents 
// in the fruits namespace.
std::string myQuery = "collection('exampleData.dbxml')/fruits:product";

// Perform the query.
XmlResults results = myManager.query(myQuery, context);

// Delete everything in the results set
XmlUpdateContext uc = myManager.createUpdateContext();
XmlDocument theDoc = myManager.createDocument();
while (results.next(theDoc)) {
    myContainer.deleteDocument(theDoc, uc);
}