Detect, count, chart text field differences between months

[Anonymous]

My data looks like this...

Year	Month	Year_Month	Emp_ID	YR_MO_EID_Key	Business Unit
2011	12	201112	1001	2011121001	ENT
2011	12	201112	1002	2011121002	SMB
2012	1	201201	1001	2012011001	ENT
2012	1	201201	1002	2012011002	FND
2012	1	201201	1003	2012011002	ENT
2012	2	201202	1001	2012021001	SMB
2012	2	201202	1002	2012021002	FND
2012	2	201202	1003	2012021003	SMB

...and I want to make a bar chart that shows the number of employees that have transferred into a business unit by month.  A table of this output would look like this...

Month	ENT	SMB	FND
DEC-11	-	-	-
JAN-12	0	0	1
FEB-12	0	2	0

The first row is empty because there is no data prior to DEC-11.  Also, note that a new employee (1003) appears in JAN-12.  This new employee should not count as a transfer into a business unit.  If an employee stays in a business unit, that also should not count as a transfer into that business unit.  For a given month and for a given business unit, I only want to count the number of employees that a) existed in the previous month and b) changed business units to the given business unit.  How can I do this and put the monthly numbers in a bar chart?

[CELAMBARASAN]

You need to create a field in the load script as a flag whether the employee is trasferred or not.

like

Load *, if(peek('Emp_ID') = Emp_ID and peek('BusinessUnit') <> BusinessUnit , 1, 0) AS IsTransferred;

Load

Year,Month,Year_Month,Emp_ID,YR_MO_EID_Key,BusinessUnit

From ...

Order by Year_Month,Emp_ID;

Then expression as

Sum(IsTransferred)