Can Maximo formulas return null?

问题

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In Maximo 7.6.1.1:

I have an attribute formula on a persistent field called WORKORDER.X. The field type is decimal, length is 18, and scale is 10.

The formula is meant to do this:

• If WOSERVICEADDRESS.LONGITUDEX is not null, use it
• Else, if ASSET.X is not null, use it
• Else, if LOCATION.X is not null, use it

This is the expression I've come up with:

NVL(SERVICEADDRESS$LongitudeX, NVL(ASSET$X, NVL(LOCATION$X,0) ) )
                                                           ^
                                           I would prefer null, not 0

---

Question:

If all of the search-values end up being null, is there a way to return null, rather than 0?

I've tried using the word null, but I get an error:

BMXAA9399E - This formula is invalid because the following attribute or token is 
             invalid: null. Specify a valid attribute and try again.

I've also tried "", but that returns 0.

And using a field who's value is null also throws an error.

来源：https://stackoverflow.com/questions/59447159/can-maximo-formulas-return-null