Divide a value in one column by the corresponding value in another

[lewdow]

Hi - I have 2 tables, one containing a PRODUCT_VOLUME column and one containing a REGISTER_SIZE column. Both columns are linked by LEGAL_ID as the unique identifier (an additional column in both tables)

I want create a new column (as there is one row per month to this data and want to show it on a time chart) to divide the PRODUCT_VOLUME for the specific LEGAL_ID by the REGISTER_SIZE for that specific LEGAL_ID. 

I'm a bit of a novice and so if anyone can help with the DAX that would be appreciated!

[ccapowerbi]

@lewdow 

Hey!

When I have two tables (A & B) and want to reference a value in a column in table B in a calculated column in table A when they are related, I use the LOOKUP expression. 

Maybe in your situation you can use something like this:

New Column =
DIVIDE(
  PRODUCT_VOLUME,
  LOOKUP(
     REGISTER_SIZE table[REGISTER_SIZE column],
     REGISTER_SIZE table[LEGAL_ID column],
     PRODUCT_VOLUME table[LEGAL_ID column]
     )
)

Something like this could be used if adding a calculated column in the table that contains the PRODUCT_VOLUME column.

[lewdow]

Thanks, can't quite get it to work. Shoudl it be LOOKUPVALUE instead of just LOOKUP?

[lewdow]

The error I get when using LOOKUPVALUE appears to not be able to find the REGISTER_SIZE table - is there something special I need to add in to get it to recognise looking at another table?

[ccapowerbi · Accepted solution]

Hey @lewdow 

I should have used LOOKUP value; sorry about that. 

I tested this out & here is my DAX for the calculated column:

Product/Register = 
DIVIDE(
    Product_Volume_Table[Product_Volume],
    LOOKUPVALUE(
        Register_Size_Table[Register_size],
        Register_Size_Table[Legal_id],
        Product_Volume_Table[Legal_id]
    )
)

Keep in mind I don't know the name of your tables, so the name of my tables are probably different than yours. I'm including my pbix file so you can see how I have things set up. 

Click HERE to access my pbix file.

[lewdow]

Perfect thank you!