There is a lot of discussion about the use of Mock Objects to aid in unit testing. One of the advantages of this approach is that you can abstract away things like a Data Access Layer so that you can test just the Business Logic layer. What do you do, however, when it is the Data Access layer that you are trying to test? ADO.Mock is an attempt to answer that question. It provides a complete ADO.Net implementation for both .Net 1.1 and .Net 2.0, and allows you to create sample data for your tests, and then write SQL queries or stored procs around that data. The default input for this data is a DataTable object, so you could even take a snapshot of production or test data to use as the basis of your mock data. All standard SQL operations are supported through a basic SQL parser, so you can even test data access components which generate SQL automatically.