Forum Discussion
Why does this formula work? Filter(all(...
Anonymous
Yes, I know it is confusing...It takes a while to get your head around it (I've been at this for over 3 years and I learn stuff every day!).
We are back to a previous stage in the explanation. The whole FILTER expression contains 2 parts:
1) ALL removes the filters from the date table
2) THEN the second filter expression kicks in. What it's doing is seeing an unfiltered dates table (since ALL has removed the filters), and then it returns the values established in the second expression over the whole dates table. Since the second filter expression checks the week number column, which does have a value "selected", it applies the new filter based on that selected value.
Your second expression refers to the value selected in the week number column and a year. So it applies the filters accordingly over the whole date table.
But should this not then return all weeks in the table...all 52 weeks and not just to week 5 that the slicer filters to?
Anonymous you think MAX ( 'Date'[Week Number] ) returns the 52th week of the year? What dissapoints you is that it's NOT the case.
As MAX ( 'Date'[Week Number] ) corresponses to
MAXX( 'Date', 'Date'[Week Number] )you get the week number you've chosen. It's all about filter context in DAX. Sounds a bit off the topic from your issue but it's the very conerstone of any DAX calcuation. Here's a classic article on such a subject; one can never read it too many times.
CNENFRNL Thank you for the article, i will read it later today.
I'm actually happy with the original solution, i just didn't understand why it worked. i.e. why the all('date table') didn't remove the slicer filter eventhough the slicer filter uses the week column in the date table! I still dont!
Anonymous It seems to me that you didn't wrap your head around the order of calculation here. For FILTER func,
- it evaluates in the first place ALL('Date'), the full table of 'Date'
- secondly all those filtering criteria, i.e. 'Date'[Week Number]<=max('Date'[Week Number]) && 'Date'[Week Year]= max('Date'[Week Year]) is applied to full 'Date' table.
Thanks for the swift response. Sorry if i'm being dense but surely this means that by clearing the filters from my table it provides the full list of weeks, not just those filtered in the slicer?
- it evaluates in the first place ALL('Date'), the full table of 'Date' - so it removes the slicer filter which filtered to week 5
- secondly all those filtering criteria, i.e. 'Date'[Week Number]<=max('Date'[Week Number]) && 'Date'[Week Year]= max('Date'[Week Year]) is applied to full 'Date' table. and therefore it should bring back week 1 to 52 as there are 52 weeks in the table
?