Autocalculate dff value based on other dffs

Summary:

Hi,

Business has a requirement where they want to autocalculate a dff's value as sum of values entered in earlier dffs.

For example,

DFF1 value entered : 100

DFF2 value entered: 200

DFF3 value : 300 (Auto-calculated by system)

How can we achieve this in Oracle system? Is it possible to do so?

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