Database Rules

Rules define the way a business keeps track of its data. They apply only to update programs; they have no function in reporting programs. You can define rules for a file, a state, or an event (referred to here as file rules, state rules, and event rules, respectively). The system structures the rules hierarchically. That is, file rules apply to all records in the file and all states and events defined in the file, state rules apply to all records in that particular state and all events defined in the state, event rules apply only to records in that event. You can also define any of these rules to apply globally across the entire file, or only to particular subtypes you have defined.

When an event causes multiple rules to be applied, all conditional rules, such as Field Relation or Required rules, must evaluate True; otherwise, no rules that modify the data take effect. If any conditional rule evaluates to False, the event terminates with an error message and the system discards any results of rules that modified data. See Field Relation for more information.

For the procedure to define database rules, see Defining Database Rules.