Fill Blanks of Column Based on Value of Another Column

[nickhukriede]

I have the following setup in my table:

Tag1Dec (numerical data) and a FishSpecies associated with that data. The problem is we may only have 1 fish species but many duplicate Tag1Dec. I am attempting to fill the FishSpecies by already previously known numbers from Tag1Dec. Image and explanation below:

As you can see I have a FishSpecies = "LL" for the Tag1Dec = 989001033212881. There are multiple rows with the same Tag1Dec value and I would like to populate the FishSpecies with the corresponding "LL" that is in the first row.

[v-easonf-msft · Accepted solution]

Hi,  @nickhukriede 

You can replace all blank value with null and then fill down cell values.

You can also try to create a calculated column as below:

FishSpecies2 =
CALCULATE (
    MAX ( 'Table'[FishSpecies] ),
    ALLEXCEPT ( 'Table', 'Table'[Tag1Dec] )
)

Best Regards,
Community Support Team _ Eason

[Anessa]

Hi @v-easonf-msft,

Thanks for your reply, I found this solution work perfectly. Could you please help explain the logic behind it as I am not familiar with these DAX functions? Thanks a lot!