PREVIOUSMONTH with null current month

[powerinbi]

Hi everyone!

I am in a situation where I have a table with 3 columns: Asset name, Month, Depreciation.
I am using PREVIOUSMONTH to find the depreciation for an asset 1 month ago.

However, if an asset is not having any depreciation in current month, then there simply is not a row for current month. In that situation, the PREVIOUSMONTH returns 0 and not the actual previous month value.

For example, how do I use the previous month formula here, so that it returns 150 (not 0) for asset 10001 and 200 for 20002?

Asset	Month	Depreciation
10001	03-2021	150
20002	04-2021	100
20002	03-2021	200

Thanks!

[Anonymous · Accepted solution]

@powerinbi 

Before you start doing any time-intel calculations, I'd strongly and kindly advise you familiarize yourself with how such things work. You can start with this: Time Intelligence in Power BI Desktop - SQLBI

Quick Hint: You are not using the time-intel function with a real date table so the result will be wrong, even if SOMETIMES it will be correct.