Comparisons between ADO and ADO.NET

Apart from its disconnected nature, the other key advantages of ADO.NET over ADO are: Whereas ADO.NET uses DataSets to hold data, ADO uses the RecordSet object. An ADO RecordSet represents a single table so, even if you join multiple tables, its view will be of a single table – it is not possible to work with multiple tables at once. The ADO.NET DataSet, on the other hand, contains a collection of tables and the relationships between them, so is able to handle a much more complex data structure.

The ADO.NET DataSet provides both a table-based relational view and an XML-based hierarchical view, and either can be used interchangeably. See Chapter 12 for more on this. The ADO RecordSet stores data in binary format, which can be a problem because firewalls tend to block binary data transfers. XML is a text-based data format, so ADO.NET can transfer data more easily and reliably through firewalls.

XML also permits an unlimited variety of data types, and incorporates ways to validate that the correct data types are used. Because ADO uses COM as a transportation mechanism, performance can be hindered by translation to and from the limited COM data types.

With ADO, there was always the problem of having the correct version of MDAC to access your data, but ADO.NET supports side-by-side versions of ADO.NET without having to worry about versioning issues.