Cannot replace Measures with Variables

[Neha_PowerBI]

Hi,

I have a measure 

Calculated Buy  =

var SalesStock = [Sales] + [Stock]

Return

IF( [Buy] <> BLANK(),

IF( [Buy] > SalesStock, [Buy], SalesStock ))

and then I pass it through another measure

Calculated Buy New =

SUMX(

    SUMMARIZE(

        'Article', 'Article'[Division], 'Article'[Gender], 'Article'[Code], 'Article'[Type], 'Article'[RBU], "Total",[Calculated Buy Value]),

        [Total]    

)

I get the correct Total. But if I try to remove the Measure and include it in Calculated Buy as a variable. It's giving me incorrect Totals. Can anyone please help me to undesrant what's wrong in the below code:

Calculated Buy New =
var Buy  =

var SalesStock = [Sales ] + [Stock_]

var Check = 

IF( [Buy] <> BLANK(),

IF( [Buy] > SalesStock, [Buy], SalesStock ))

SUMX(

    SUMMARIZE(

        'Article', 'Article'[Division], 'Article'[Gender], 'Article'[Code], 'Article'[Type], 'Article'[RBU], "Total",[Check]),

        [Total]    

)
Thanks in advance. 

@variables @sumx

[johnt75 · Accepted solution]

Variables aren't really variable, they're constants. They're only calculated once when you define them, so they're useful for storing the results of a calculation if you want to refer to it multiple times but if you need to perform the same calculation multiple times with different filter contexts then you cannot use variables for that.

Also, a couple of general points. You shouldn't use SUMMARIZE to add calculated columns to a table, you should use SUMMARIZE just to give the static columns and wrap it in ADDCOLUMNS to add the calculations.

And you shouldn't use equality operators to compare to blank as that can give unexpected results, as 0 equals blanks. Instead of variable <> BLANK(), use NOT(ISBLANK(variable)).