Query Entity

You cannot do this directly with query entity, but you could apply over the result with a APN_replaceNull from Appian Common Objects.

But here, I am not not fetching NEW_CD and OLD_CD. Based on the NVL condition I want to fetch the records. How APN_replaceNull helps?

You would need to query for both columns. Then replace the null values of the one column with the results of the other.

In other words, you would need to do some processing on the Appian side in addition to the database side.

You could also create a database view for your REQUEST table, creating a new column for NVL(NEW_CD, OLD_CD). Then through your Appian queryEntity, have a filter to check where this new column is IN (1,2,3).

Yes, view is the best option. But we don't have time. Trying from Appian side to resolve this issue. How to get the records from REQUEST CDt variable where NEW_CD IN (1,2,3)?

I think you can accomplish this by using logicalExpressions. You can use logicalExpressions to combine filters, so for example you could make a logicalExpression that checks if NEW_CD IN (1,2,3) OR (NEW_CD is null AND OLD_CD in (1,2,3)) .Check out this link: forum.appian.com/.../System_Functions.html