ADO 2.5 and XML
Using ADO 2.5, you can read data from nearly any data source, place the data into an ADO recordset (which is similar to a virtual table containing the data in memory), and transform the data to XML. Once the data has been transformed to XML, it can be placed into a data stream and used as output to various sources, such as a file, the ADO ASP Response object (which is used to return information to the Web client), and the XML DOM. Outputting the data as XML can be accomplished by using the COM IStream interface. The IStream interface is an interface designed to support reading and writing data to ADO Stream objects. ADO 2.5 requires support for the IStream interface.
On the other hand, XML data can be used as a data source of a read-only or read/write recordset in ADO 2.5. For example, you can use ADO 2.5 in an ASP page on a Web server to retrieve data from a database by placing the data into an ADO recordset. The data will then be transferred as XML output to the ASP Response object using ADO 2.5. Once the XML data arrives on the client, it can be read into an ADO recordset on the client using DHTML. Using the client-side ADO recordset and DHTML, the user can read and update the data. Let's look at several examples of inputting and outputting data as XML in ADO 2.5 to see how this works.