MinDate For Each Unique Record & Group

Hey Anonymous ,

 

I created two calculated columns two answer your first question "earliest date".
The first calculated column repeats the the earlies date for each person:

Earliest Date = 
var currentPerson = 'Table'[PRS_ID]
var currntDate = 'Table'[BGN_DATE]
var minDate = 
MINX(
    FILTER(
        'Table'
        , 'Table'[PRS_ID] = currentPerson
    )
    , [BGN_DATE]
)
return
minDate

The second  column flags the earliest data for each person:

Is Earliest Date = 
var currentPerson = 'Table'[PRS_ID]
var currntDate = 'Table'[BGN_DATE]
var minDate = 
MINX(
    FILTER(
        'Table'
        , 'Table'[PRS_ID] = currentPerson
    )
    , [BGN_DATE]
)
return
IF( minDate = currntDate, "TRUE" , "FALSE" )

The table will look like this:

The second question "number of persons per month" can be solved by

• creating a dedicated calendar table that also has a period colum
• create a relationship between the calendar table (one-side of the relationship) and the existing table
• create a table visual that uses the period column from the calendar table
• use the perion-id column to the table visual and change the aggregation function of the the column to count distinct

This article explains basically everything about date-related calculation: Time patterns – DAX Patterns

This article provides an introduction to data modeling in Power BI: Design a data model in Power BI  - Learn | Microsoft Docs

 

Hopefully, this helps to tackle your challenge.

 

Regards,

Tom