Code Dilemma

Question

Hello everyone,
                          In ABAP, how do I check to see if a field is null and if it is then fill it in with some value.  I have the following statement however, I am pretty sure this not correct because it seems to overwrite all my dates with current system date.  So If this code runs today it will put in system date for all the records coming in but if I run this code tomorrow it will replace the date with tomorrow's date which is useless.
Select * from /BI0/MProfit_Ctr into table lt_profit_Ctr.
Read table lt_profit_Ctr with key PROFIT_CTR = /BI0/MPROFIT_CTR.
if sy-subrc <> 0 or lt_profit_Ctr-CALDAY IS INITIAL.
RESULT = SY-DATUM.
ENDIF
If a record for a profit center is there but the date is not there it is supposed to put in a current system date for that record but if a profit center is there with a date it MUST not do anything and move on and if profit center is not there then add it with a date.
Please let me know your ideas,
Syed.

Answer 1

sorry actually the statement goes like this
update /BI0/MProfit_Ctr with wa_profit_Ctr transporting calday.
what this statement will do is that when calday is initial for the particular record u have retrieved it will assign the system date to the work area of the retrieved record but then u need to update ur database table back with this data so we use update statement.
but again i'm not sure why are u using read instead of loop at if only one record is getting retrieved use select single.
and
this is the code u posted above
Select * from /BI0/MProfit_Ctr into table lt_profit_Ctr.
Read table lt_profit_Ctr with key PROFIT_CTR = /BI0/MPROFIT_CTR.
if sy-subrc 0 or lt_profit_Ctr-CALDAY IS INITIAL.
RESULT = SY-DATUM.
ENDIF
i have some doubts in this code, please clarify those
Read table lt_profit_Ctr with key PROFIT_CTR = /BI0/MPROFIT_CTR.
whats the thing i have marked in red, i see that its the same as ur table name what condition u r trying to check in read table.
i think it shud go like this.
Select * from /BI0/MProfit_Ctr into table lt_profit_Ctr
where PROFIT_CTR = <some variable having ur profit_ctr>
now loop at and rest of the code is same as above discussion
if u r sure that only one record is going to get retrived then
use
select single * from /BI0/MProfit_Ctr into wa_profit_Ctr
where PROFIT_CTR = <some variable having ur profit_ctr>
then update /BI0/MProfit_Ctr with wa_profit_Ctr.
if i'm wrong then please explain ur requirement for us to help u better.
regards,
kartik
Edited by: kartik tarla on Dec 20, 2008 9:23 AM