Chapter 1-3: Data Dictionary

An Example of a Domain

One example of a domain might be employee number which should have the same number of characters and the same editing characteristics wherever it is used in a system. You can define such common attributes—including a descriptive name if desired—once, in an EMPLOYEE NUMBER domain. Domain attributes apply to all fields referencing that domain and cannot be overridden at the field level. Thus, any attributes that are not appropriate for each field based on the domain should be left blank in the domain definition. For instance, the employee master file may include employee number fields for both the employee and the employee’s supervisor. While "Employee Number" is a good descriptive name for the first field, "Supervisor Number" is more appropriate for the second field. To accommodate this situation, just leave Descriptive blank in the domain definition and enter individual names instead. Meanwhile, both employee number fields remain subject to the same format and editing criteria defined for the domain.

APPX Application Design Manual (01/13/03)

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