We present methodology, which allows automatically test database schemes. Such methodology allows you to create new one or expand existing CASE tool. You can integrate database tests in generating physical database model process. In this way you can make scheme validation much easier, as a result it lowers the possibility of errors in early steps of modelling. Acording to our analysis, there are very few tools that covers such methodotlogy. So during our work we have designed and created a new tool – „DbTestAddin“, tool that tests database schemes. It works as Microsoft Office Visio 2003 Add-in. With this tool you can easily test any database scheme you want, compare it with a real database etc. In future, there are several updates and functional enhacements which can make this tool more attractive to use.