cancel
Showing results for 
Search instead for 
Did you mean: 
Reply
andrewsk Frequent Visitor
Frequent Visitor

FILTER on multiple tables

Hi all. I am new to DAX and am having a hard time getting my head around the FILTER command.

 

I want to Filter Data based off of multiple tables (Properly joined via many to one relationships) Here is an example.

 

This works fine:

FILTER(

'Product Data', 'Product Data'[ProductCategory]="Mountain Bikes"

 

When I add another Table it breaks:

FILTER(

'Product Data', 'Product Data'[ProductCategory]="Mountain Bikes"

&& 'Sales Data'[Unit Price]>1000)) 

 

The error message I get is that "'Sales Data' cannot be found or may not be used in this expression"

 

My guess is that because FILTER only returns the defined Table, adding in another table messes it up, so I probably have to wrap the second parameter in something...

 

 

Thankyou in advance!!

1 ACCEPTED SOLUTION

Accepted Solutions
Highlighted
Super User
Super User

Re: FILTER on multiple tables

Hi @andrewsk

 

As a NEW TABLE, try this

 

New Table=
FILTER (
    'Product Data',
    'Product Data'[ProductCategory] = "Mountain Bikes"
        && CALCULATE ( AVERAGE ( 'Sales Data'[Unit Price] ) > 1000 )
)


FILTER function is an interator. All ITERATORs (like FILTER,SUMX,MAXX etc) work in folllowing fashion.
1) They create a ROW context on the TABLE received as first argument

2) They evaluate the second expression for each ROW of that TABLE


However FILTER only provides ROW context and not the FILTER context.
Calculate transforms that row context into filter context allowing you to work with relationships

7 REPLIES 7
Phil_Seamark Super Contributor
Super Contributor

Re: FILTER on multiple tables

Hi @andrewsk

 

You can pass multiple FILTER functions to CALCULATE, so maybe try simething like this?

 

 

My Calc = CALCULATE(
		SUM(something) , 
		FILTER('Product Data', 'Product Data'[ProductCategory]="Mountain Bikes") , 
		 FILTER('Sales Data'[Unit Price]>1000)
		 )

 


To learn more about DAX visit : aka.ms/practicalDAX

Proud to be a Datanaut!

andrewsk Frequent Visitor
Frequent Visitor

Re: FILTER on multiple tables

First, thanks for your response:

 

I got this to work:

Road Bikes >1 = CALCULATE(

SUM('Sales Data'[Number sold]),
FILTER('Product Data', 'Product Data'[ProductCategory]="Road Bikes"),

FILTER('Sales Data','Sales Data'[Number sold]>1))

 

 

I understand that CALCULATE is allowing this and that is awesome.

 

HOWEVER, I still don't understand why I cant write a FILTER statement (Using"New Table") on multiple tables without having to SUM, AVERAGE, etc. the data within CALCULATE.

 

What if I just want to FILTER the data exactly as it is in the first table, with some criteria from a second joined table without having to go the reports?

I feel like I am missing something here...

 

andrewsk Frequent Visitor
Frequent Visitor

Re: FILTER on multiple tables

Duplicate reply

Phil_Seamark Super Contributor
Super Contributor

Re: FILTER on multiple tables

The CALCUATE function is pretty handy and you can do some pretty powerful stuff with it if you need to.  


To learn more about DAX visit : aka.ms/practicalDAX

Proud to be a Datanaut!

Highlighted
Super User
Super User

Re: FILTER on multiple tables

Hi @andrewsk

 

As a NEW TABLE, try this

 

New Table=
FILTER (
    'Product Data',
    'Product Data'[ProductCategory] = "Mountain Bikes"
        && CALCULATE ( AVERAGE ( 'Sales Data'[Unit Price] ) > 1000 )
)


FILTER function is an interator. All ITERATORs (like FILTER,SUMX,MAXX etc) work in folllowing fashion.
1) They create a ROW context on the TABLE received as first argument

2) They evaluate the second expression for each ROW of that TABLE


However FILTER only provides ROW context and not the FILTER context.
Calculate transforms that row context into filter context allowing you to work with relationships

andrewsk Frequent Visitor
Frequent Visitor

Re: FILTER on multiple tables

Thank you for your reply. I have a final question if you don't mind. 

 

So in your example: 

New Table=
FILTER (
    'Product Data',
    'Product Data'[ProductCategory] = "Mountain Bikes"
        && CALCULATE ( AVERAGE ( 'Sales Data'[Unit Price] ) > 1000 )
)

 

When you are using AVERAGE, is it just to trick the code into using the FILTER context?

 

The actual data returned from this would be AVERAGED for each row, so it would not change. (IE the Average of a Unit Price of $1500.00 on a single row is still $1500.00. ) Smiley Happy

Super User
Super User

Re: FILTER on multiple tables

Hi @andrewsk

 

I believe this is how it works.

 

Assuming there is a one to many relationship between Product and Salesdata

 

1) The argument "CALCULATE ( AVERAGE ( 'Sales Data'[Unit Price] ) > 1000" is evaluated for each ROW of the PRODUCT Table.

 

2) Since we use CALCULATE INSIDE a ROW CONTEXT, it transforms that ROW context into a FILTER CONTEXT.

Meaning that... for each product it goes to SALESDATA table, fetches the ROWS that are related to that product and takes an average of those products

 

3) It that average is >1000, the Row of the Product Table is retained

else it is filtered out