Database systems play an important role in nearly every modern organization, yet relatively little research effort has focused on how to test them. This paper discusses issues arising in testing database systems and presents an approach to testing database applications. In testing such applications, the state of the database before and after the user's operation plays an important role, along with the user's input and the system output. A tool for populating the database with meaningful data that satisfy database constraints has been prototyped. Its design and its role in a larger database application testing tool set are discussed.