Count most common string, filter based on values across tables

[bwyker]

Appreciate any help with this logic problem.

I have three tables

1 - MEMBERS

ID | FirstName | LastName | ...

81    Joe              Smith

22    Jane            Doe

31    Bob             Jones

2 - EVENTS

event_id |  eventDate  | eventDiscipline | ....

998          01/01/2017   Yoga

999          01/02/2017   Boxing

1000       01/03/2017    Boxing

3 - ATTENDANCE 

event_id | ID

998          81

998          22

999          22

999          31

1000        22

That tables are joined together by event_id and ID. So, in this example Joe and Jane attended Yoga on 1/1, Jane and Bob attended Boxing on 1/2. and Jane was the only attendee at boxing on 1/3. 

I am trying to add a column to the MEMBERS table (or wherever it makes sense) that would tell me the discipline the person attended most often and use the discipline name as the value. So, based on the example above, it would look like this:

ID | FirstName | LastName | EventMost

81    Joe              Smith        Yoga

22    Jane            Doe           Boxing

31    Bob             Jones        Boxing

I'm assuming I will have to first create a colomun in the MEMBER table for each that is a count the event_id for each discipline, then search across these new columns for the highest value? 

I'm new to DAX, so please forgive my ignorance in advance.

[v-ljerr-msft · Accepted solution]

Hi @bwyker,

Based on my test you should be able to follow steps below to get your expected result.

1. Use the formulas below to create two new calculate columns in ATTENDANCE table.

eventDiscipline = RELATED(EVENTS[eventDiscipline])

Count_of_eventDiscipline = 
COUNTROWS (
    FILTER (
        ALL ( ATTENDANCE ),
        ATTENDANCE[ID] = EARLIER ( ATTENDANCE[ID] )
            && ATTENDANCE[eventDiscipline] = EARLIER ( ATTENDANCE[eventDiscipline] )
    )
)

2. Then you should be able to use the formula below to add a column to the MEMBERS table that would tell you the discipline the person attended most often and use the discipline name as the value.

MostOfenEventDiscipline = 
VAR maxCount =
    CALCULATE ( MAX ( ATTENDANCE[Count_of_eventDiscipline] ) )
RETURN
    CALCULATE (
        FIRSTNONBLANK ( ATTENDANCE[eventDiscipline], 1 ),
        ATTENDANCE[Count_of_eventDiscipline] = maxCount
    )

Here is the sample pbix file for your reference. 

Regards

[bwyker]

This worked perfectly! Thank you SO much for the quick response and the super efficient solution. Very much appreciated!