A domain defines a value range. A domain is assigned to a data element. All table fields or structure components that use this data element then have the value range defined by the domain. The relationship between the field or component and the domain is thus defined by the data element of the field or component.
Fields or components that refer to the same domain (with the assigned data elements) are also changed when the domain is changed. This ensures that the value ranges of these fields or components are consistent. Fields or components that are technically the same can thus be combined with a reference to the same domain.
The value range of a domain is defined by specifying a data type and length (and number of decimal places for numeric data types).
A personnel number is defined by the data format NUMC and by specifying the number of places for this personnel number.
The value range of a domain can be restricted by definingfixed values. If all the fields or components that refer to the domain should be checked against a certain table, this table can be defined as the value table of the domain.
Output attributes can also be defined for all the fields or components that refer to the domain (seeCreating Domains). A conversion routine can be assigned to a domain. This conversion routine converts values from display format to internal format for the fields or components that refer to this domain.
See also:Creating Domains Changing Domains Deleting Domains