DAX: calculate difference between date/times with conditions

[Dicko]

Hi,

I have data of telephone calls with details of each call.

Now I need to calculate the duration of each call if the reason is completed.

So for the call with call_id 123 the duration is 4 minutes.

I have no idea where to start ...
I really would like to learn how to do this.

[Fowmy · Accepted solution]

@Dicko 

Add the following code as a new column to your table:

Difference = 

VAR __ID = Table2[call_id]
VAR __TIME = Table2[timestamp]
RETURN

IF(
    Table2[reason] = "completed",
    DATEDIFF(
        CALCULATE(
            min(Table2[timestamp]),
            Table2[call_id] = __ID,
            Table2[timestamp] < __TIME,
            REMOVEFILTERS(Table2)
        ),
        __TIME,
        MINUTE
    )
)

[Dicko]

Thanks! I learned something new 🙂