Derived Field

A field that has its value determined automatically by a predefined specification called a Derivation Formula. DataEase offers four kinds of Derived fields: Calculated, Lookup, Sequenced, and Default.

The value in a:

Calculated field is determined using a predefined mathematical formula. For example, DataEase can derive the value of a TOTAL COST field by calculating PRICE x QUANTITY.

Lookup field is retrieved from a field in a related form. For example, when you enter a CUSTOMER NUMBER in an INVOICES form, DataEase can look up the value of the CUSTOMER NAME, ADDRESS and PHONE NUMBER fields from a related form.

Sequenced field is incremented by one each time a new record is entered into a file. For example, DataEase can assign a unique, sequenced value to the INVOICE NUMBER field in each INVOICES record.

Default field is automatically entered by DataEase during record entry. For example, if most of your customers live in the same city, you can let DataEase enter default values in the CUSTOMERS CITY, and STATE fields. You can override a Default field value simply by typing over it.