Understanding Your Data Model › Using Fields › Using Function Fields › Maximum (MAX)

Maximum (MAX)

The MAX usage type is given to function fields that contain the highest value found for a field over a series of records.

A function field of usage type MAX has two parameters:

• Result parameter—The derived field itself. This must be placed on a total format of any function, which calls the MAX function.
• Input parameter—The field for which the highest value is to be determined. 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, within an Edit Transaction function, a MAX field defined on the header could be used to calculate the maximum value of a field on the subfile record.

Fields of type MAX must always be numeric. If the function field is defined as a REF field, based on another numeric field, assumes that the based-on field is the field whose highest value 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 MAX fields include:

• Largest order item : maximum of order quantity
• Biggest warehouse location : maximum of location size
• Largest town : maximum of town size
• Highest line number : maximum of line number