We propose a new method for integrity checking in deductive databases.The methodaugmentsadatabasewith asetof transition and internal eventsrules,which explicitly definetheinsertionsanddeletions induced by a databaseupdate. Standard SLDNF resolution can then be used to checksatisfactionof integrity constraints. The method has the full power of the methods developed so far, and its implementation in Prologdoesnot require any meta-interpreter. A second main advantageis that it deals with both static anddynamicintegrityconstraints,providing a simple and uniform approachin which bothclassesof integrity constraintscanbe definedandefficiently enforced.