Patent US 5,488,722

Disclosed is a system and method of operating a computer to update a database. An entry made by a user for creating, deleting or modifying an entity type instance is checked to determine applicable constraints, which are then activated and placed in a pool. A firing order is then determined for the activated constraints. The first ranked constraint is then coded, using database calls if necessary to provide data for the logical statements, after which the coded constraint is fired. If the constraint was violated an error is signalled and processing is returned to the step of activating constraints for treatment of revised user data. Otherwise, it is determined if any constraints remain to be fired before returning to the step of activating or exiting.