list difference from previous month data

[babarbashir]

DAXI have a month wise employee data (sample below) and I want to calculate the leavers (removed) and joiners(added) by month. 

e.g. Jan 2016, I want to know many entries removed and how many new entries added vs dec 2015, feb 2016 vs jan 2016 and so on in a single query.

Any help would be appreciated.

Regards,

Year	Month	Branch	Emp Name	Emp No
2015	12	B1	Emp1	1
2015	12	B2	Emp2	2
2015	12	B1	Emp3	3
2015	12	B2	Emp4	4
2015	12	B1	Emp5	5
2015	12	B1	Emp6	6
2016	1	B1	Emp1	1
2016	1	B2	Emp2	2
2016	1	B1	Emp3	3
2016	1	B2	Emp4	4
2016	1	B1	Emp7	7
2016	1	B1	Emp6	6
2016	1	B2	Emp8	8
2016	2	B1	Emp1	1
2016	2	B2	Emp2	2
2016	2	B1	Emp3	3
2016	2	B1	Emp7	7
2016	2	B1	Emp6	6
2016	2	B2	Emp8	8
2016	2	B1	Emp9	9
2016	2	B2	Emp10	10
2016	2	B1	Emp11	11
2016	2	B2	Emp12	12
2016	3	B1	Emp1	1
2016	3	B2	Emp2	2
2016	3	B1	Emp3	3
2016	3	B1	Emp7	7
2016	3	B2	Emp10	10
2016	3	B1	Emp11	11
2016	3	B2	Emp12	12
2016	3	B2	Emp13	13
2016	3	B2	Emp14	14
2016	4	B1	Emp1	1
2016	4	B2	Emp2	2
2016	4	B1	Emp3	3
2016	4	B1	Emp7	7
2016	4	B2	Emp10	10
2016	4	B2	Emp14	14

[Eric_Zhang · Accepted solution]

@babarbashir

In my opinion, you will need some calculcated columns, a calendar table and some measures in this case.

calculated columns

Date = DATE(Entries[Year],Entries[Month],1)

if last month's entry exists = 
SWITCH (
    TRUE (),
    CALCULATE (
        VALUES ( Entries[Emp No] ),
        FILTER (
            ALL ( Entries ),
            EARLIER ( Entries[Branch] ) = Entries[Branch]
                && EARLIER ( Entries[Emp No] ) = Entries[Emp No]
                && EARLIER ( Entries[Date] ) = DATEADD ( Entries[Date], +1, MONTH )
        )
    )
        = BLANK (), "N",
    "Y"
)

Measures

new entries = CALCULATE(COUNTROWS(Entries),Entries[if last month's entry exists]="N")

removed entires =
COUNTROWS (
    FILTER (
        ALL ( Entries ),
        MAX ( 'Calendar'[Date] ) = DATEADD ( Entries[Date], +1, MONTH )
    )
) // last month's entries
    - ( COUNTROWS ( Entries ) - [new entries] )

Check more details in the attached pbix.