Union three columns across three tables

[Daniel48]

Hello, 

Is it possible to create a column that only has distinct values from 3 columns on 3 different tables. I found the formula below but it keeps giving me errors.

Thank you in advance!

Country = FILTER(
    DISTINCT(UNION(VALUES('4 - Data (CSAT)'[Country]), VALUES('4 - Data (Voice)'[Country]))),
    [Country] <> BLANK()
)

[lbendlin]

Before you can do a UNION your columns need to have the same name.  Use SELECTCOLUMNS  to rename them as needed.

[Daniel48]

Master Policy Table = FILTER(DISTINCT(UNION(VALUES('policy finance_Initial'[policy_uniqueid]),VALUES('policy finance_target'[policy_uniqueid]),VALUES('policy premium'[policy_uniqueid])),

    [policy_uniqueid] <> BLANK()))

I have renamed the columns but I am getting the error. Too many arguments were passed to the DISTINCT function. The maximum argument count for the function is 1. I can get it with two columns but not three

[lbendlin · Accepted solution]

try this

Master Policy Table =
FILTER (
    DISTINCT (
        UNION (
            VALUES ( 'policy finance_Initial'[policy_uniqueid] ),
            VALUES ( 'policy finance_target'[policy_uniqueid] ),
            VALUES ( 'policy premium'[policy_uniqueid] )
        )
    ),
    [policy_uniqueid] <> BLANK ()
)

[Daniel48]

That worked perfectly! Thank you for all of your help!