New to Power BI (DAX)

[Chriswyy]

Hi guys, just started to learn power bi.

Would like to understand why error happens when I input the following formula:

=SUM(DISTINCT('Jun23 Data'[INCOME_AMT]))

Error returned: The SUM function only accepts a column reference as an argument.

Assuming below is my dataset

Month : Income_amt

Jan : 100

Feb : 100

March : 200

ps: I know this formula doesn't make sense... to sum distinct values for monthly income. But i just wanna find out how the dax works and why i cant get 300 in total.

[Jihwan_Kim]

Hi, 

If I am not wrong, DISTINCT DAX function returns a table.

However, SUM DAX function needs a column.
Please try something like below.

Or,

Expected result measure: = 
VAR _t =
    SUMMARIZE ( Data, Data[Income_amt] )
RETURN
    SUMX ( _t, Data[Income_amt] )

Expected result measure V2: = 
VAR _t =
    DISTINCT(Data[Income_amt])
RETURN
    SUMX ( _t, Data[Income_amt] )

[Chriswyy]

 hmm.. I thought it will return a column based on the documentation 

[mlsx4 · Accepted solution]

Hi @Chriswyy 

It returns a table with an unique column...That's why you need to use Sumx.
Check this at: https://dax.guide/distinct/#:~:text=DISTINCT%20DAX%20Function%20(Table%20manipulation)&text=Returns%....

Or the official link: https://learn.microsoft.com/en-us/dax/distinct-function-dax