[DAX] Why i can not use filter within summarize table?

[jaryszek]

hi,

i am doing 25 days challange from curbal and i am on day 15:
https://curbal.com/25-days-of-dax-fridays-challenge 

and i have issues with code provided in solution which is:

for me it is throwing error:

it is only working with Products[ProductID].

Can anybody explain why in simple plain english?
Please help,
Best,
Jacek

[johnt75 · Accepted solution]

In the QPurchases variable, the FILTER function is not being applied to the Orders table, it is being applied to the temporary table created by SUMMARIZE. If you try to filter on [Product ID] rather than Orders[Product ID] then that should work, as it is filtering the column from the temporary table.

Another way to do it would be to move the FILTER call inside the SUMMARIZE, so

SUMMARIZE( FILTER(Orders, Orders[Product ID] = 11 ), rest of SUMMARIZE statement

[jaryszek]

thank you very much @johnt75