Code for populating the field

Question

Hi,
can any one help me out for populating the appended field to data source.
<u><b>My requirement:</b></u> I have enhanced the data source 2lis_11_vahdr by appending the field zzmatnr in to its extract structure, Now i want to populate this field from the field available in the MARC table. so can any one help me out the whole code for this?
apart from this i have one another question that is if i append this field to the communication structure( like mcvbak, mcvbap... etc) then how we will populate this field.
and what is the exact difference between appending the field to the extract structure and appending the field to the communication structure.
Thanks

Answer 1

1)Just a sample code to add old material code(zzoldmatno) to the data source
'2LIS_02_S012'.
The function module is EXIT_SAPLRSAP_001.
You have write the code in the include zxrsau01.
when '2LIS_02_S012' .
data : it_s012biws like s012biws .
tables : mara .
loop at c_t_data into it_s012biws .
l_tabix = sy-tabix.
select single bismt from mara into mara-bismt where matnr =
it_s012biws-matnr.
if sy-subrc = 0.
it_s012biws-zzoldmatno = mara-bismt .
endif.
clear mara-bismt .
modify c_t_data from it_s012biws index l_tabix.
endloop.
2) Replicate the datasource.
3) Now with the above code datasource R/3 part is finished.To receive the new column at the BW end you have to add a column to your ODS or infocube as well to the communication structure(say ZOLDMAT in my case) and map the new field(ZZOLDMATNO) to the field (ZOLDMAT).
4) Activate the Transfer Rule.
Hope this helps.
Regs
Gopi.