Correct implementation of data constraints like referential integrity constraints and business rules is an essential precondition to ensure data consistency. Though most modern commercial DBMSs support data constraints ensurance mechanisms, constraints are often implemented in the business logic of the applications. This is especially true for non relational DBMS like Mnesia which do not provide constraints enforcement mechanisms. This case study examines a database application which uses Mnesia as data storage in order to determine, express and test the data constraints with Quviq QuickCheck and model-based testing approach.