Unit-testing should have as few barriers as possible. For relational databases those barriers range from external dependencies to speed to keeping the relational schema synchronized with your object ...

In fact, SQL Server outnumbers both of these database vendors in installed sites globally. Microsoft SQL Server has arrived!

The database schema will update and change during the lifetime of the application. When these changes are developed, the schema of environments like DEV, INT and TST will differ from the PROD schema.