The testing of database applications poses new challenges for software engineers. In particular, it is difficult to thoroughly test the interactions between an application and its underlying database, which typically occur through dynamically-generated database commands. Because traditional code-based coverage criteria focus only on the application code, they are often inadequate in exercising these commands. To address this problem, we introduce a new test adequacy criterion that is based on coverage of the database commands generated by an application and specifically focuses on the application-database interactions. We describe the criterion, an analysis that computes the corresponding testing requirements, and an efficient technique for measuring coverage of these requirements. We also present a tool that implements our approach and a preliminary study that shows the approach?s potential usefulness and feasibility.