Unable to calculate the attribute value using other attribute values within same DFF

Summary:

In the Document Records Descriptive Flexfield, one of the attribute value should be a calculated value based on the other attribute values within the DFF. Unable to get the attribute value calculated using SQL in Default value.

SQL: select FND_GLOBAL.GET_SESSION_ATTRIBUTE('a1stIterationAmount') FROM DUAL

E.g.,

1st Iteration Amount = 1200 (API Name: a1stIterationAmount)

Project % = 10 (API Name: projectTaskPercent)

Amount = 1200 * 10%

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

13

Code Snippet (add any code snippets that support your topic, if applicable):

SQL in value set: select FND_GLOBAL.GET_SESSION_ATTRIBUTE('a1stIterationAmount') FROM DUAL