Understanding Your Data Model › Using Fields › Using Function Fields › Summation (SUM)

Summation (SUM)

The SUM usage type is given to function fields, which contain the sum of the values found for another field over a series of records.

A function field of usage type SUM has two parameters:

• Result parameter—The field containing the result of the summation.

  This field must be placed on a total format of any function that calls the SUM function.

• Input parameter—The field for which the sum is to be calculated. This must be present on the detail format of the calling function.

The series of records are defined by the standard function within which the field is defined. For instance, in a Print File function, the SUM field could calculate the sum of the values in a field from the detail lines of the report, which is to be displayed in the next total format.

Function fields of type SUM must always be numeric. If the function field is defined as a REF field, based on another numeric field,CA 2E assumes that it is the sum of the values in the based-on field that is to be calculated. This method of definition cannot be used if the field to be calculated is not itself a numeric field.

Examples of SUM fields include:

• Total order value : sum of order line value
• Total warehouse space : sum of location space
• Total population size : sum of area population size