Architecting and designing : Data modeling : Components of an entity relation diagram : Objects in an ERD : Relation lines : Triggers
  
Triggers
Triggers enforce the relationship between the parent and child tables. Triggers are used to enforce business rules during database modification. For example, if the business rule is “no order records for active customers can be deleted,” a trigger may be used to control the deletion of records from the ORDER table.
System Architect automatically generates update, insert and delete triggers based on the properties of the relationship or constraint. The names of automatically-generated triggers are prefaced with it_, ut_, and dt_.
All triggers are related to specific tables; a trigger cannot be “free-standing” in the database. Depending on the DBMS, triggers may be programmed to fire after, during or instead of an action.
User-defined triggers are added to the project dictionary via the trigger editor. Trigger Templates are included with System Architect and can be used in whole or part with triggers you write. Access the templates through the Dictionary menu > Trigger Template.
See also
Relation lines