[ using advanced setfilter ]

[bolabuga]

Hello everyone, 

here is the pbix file: https://drive.google.com/open?id=0B8Aq8DhGApJqa0stb2szM2dBTUU

Im reading the "Definitive Guide to DAX" and im failing to understand a explame on chapter 10, that have the name used on the post subject.

The objective is to count the open contracts each filtered date and the book start by creating 2 measures:

FIRSTDATE = 
IF(
	ISCROSSFILTERED('DATE'[Date]);
	MIN('DATE'[Date]);
	DATE(2015;2;17))

LASTDATE = 
IF(
	ISCROSSFILTERED('DATE'[Date]);
	MAX('DATE'[Date]);
	DATE(2015;2;17))

Those 2 measures will be seeing the same date for firstdate and lastdate measures and will be used on the OPENCONTRACTS measure, where the number of open contracts will be counted.

OPENCONTRACTS V1 = 
SUMX (
 FILTER (
   CALCULATETABLE (
     ADDCOLUMNS (
       SUMMARIZE (
         CONTRACTS;
         Contracts[StartDate];
         Contracts[EndDate]);
       "NumOfOrders";
       CALCULATE( COUNTROWS ( Contracts ) )
     );
     ALL ( 'Date' )
   );
   AND ( 
       Contracts[StartDate] <= [FirstDate];
       Contracts[EndDate] >= [LastDate]
       )
   );
 [NumOfOrders]
)

Ok, for my doubt:

Why is the proposed solution on the book using firstdate and lastdate?? i have tested 2 measures (opencontracts v3 and v4) using just [TESTDATEmax] and the results are the same.

TESTDATEmax = IF(ISCROSSFILTERED('DATE'[Date]);MAX('DATE'[Date]);DATE(2015;2;17)) 

[v-huizhn-msft · Accepted solution]

Hi @bolabuga,

Based on my understanding, the firstdate and lastdate measures get the current Date[date] , then you can use it in other measure. For example, you use them as part of another measure as follows.

AND ( 
       Contracts[StartDate] <= [FirstDate];
       Contracts[EndDate] >= [LastDate]
       )

If you don't create measure to get the date, you are unable to use Date[date] directly, it will use one value in the place.

Best Regards,
Angelia 

[bolabuga]

@v-huizhn-msft

firstdate and lastdate get the current date (which is the same date in this example), and i thought i might be understanding something wrong or not seeing another use of those measures. But in this example i could use just firstdate for example and get the same result. 

Thanks for the confirmation.