1. A computer software product on a transporting medium for use in a computer system for checking and enabling updates in a database system, comprising: a rules software module separate from the code and data of the database system containing rule checks determining whether suitable preconditions exist for a modification to said database, a first command separate from the software module for carrying out the modification only when the suitable preconditions exist; linkage software for linking the first command to one or more of the rule checks in the rules module that determine if the preconditions exist; and action software for one or more rule checks within the rules module for providing alternative ways to bringing about said preconditions, if said one or more rule checks indicate the preconditions did not initially exist.