Lookup column

[CrisCros23]

Hi All,

In order to identify new documents posted during a month, I want to compare values of these documents between two dates.
In my Table i have :
One column "Dates" -> Format (dd.mm.yy)
One column "Doc number" -> Format Text
One column "Amount $" -> Format Number
To know if my document number is a new entry of last month, I want to create one column that will return "YES" if when doing a vlookup of document number under previous date (here 30.06.22) it returns an error or a nil value. Else column should return "NO"

I tried with Lookupvalue but this does not fit with Text nor Date format columns.

Thank you

Expected column answers regarding Doc Nb :
14 and 37 -> "NO"
38, 39 and 40 -> "YES"

[Anonymous]

Hi @CrisCros23 ,

The screenshot you provided is from Power BI Desktop. Do you want to use the DAX implementation in Power BI Desktop or the M implementation in Power Query?

I would recommend to add a column that contains the value from the previous row. Then you can write out your logic for the new column with references to the current row only.
If performance matters, you have to use this function to retrieve the value from the previous row: 
Fast and easy way to reference previous or next rows in Power Query or Power BI – The BIccount...

Best Regards,

Stephen Tao

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[lbendlin]

Please provide sanitized sample data that fully covers your issue. I can only help you with meaningful sample data.
Please paste the data into a table in your post or use one of the file services like OneDrive or Google Drive.
https://community.powerbi.com/t5/Community-Blog/How-to-provide-sample-data-in-the-Power-BI-Forum/ba-...

Please show the expected outcome based on the sample data you provided. Screenshots of the expected outcome are ok.

https://community.powerbi.com/t5/Desktop/How-to-Get-Your-Question-Answered-Quickly/m-p/1447523