bdc can be done in two ways
1. direct input (uses some fn modules to directly update dbtab)
2. batch input.
call transcation and session methods are the methods in batch input.
there are many differences between call transcation and session method like
1. session method is asynchronous processing and synchronous update while call transaction can use any mode for update .
2. in session method logs can be seen in session over view. in call transaction we have to handle using BDCMSGCOLL
3. session will not return sy-subrc while call transcation returns sy-subrs.
like wise there are few differences.
leaving that, the question is when to use which method.
the answer is it depends upon the scenario.
i will give u a nice example:
suppose, i need to use two transactions in my bdc.
the requirement is when the data is successfully updated in the first one, then update in the second one.
which method we need to go?
1. if we need to call two transactions, in both the methods not a problem.
2. in session method , betwwen bdc_opn_group and close_group, we can call any number of bdc_insert s in which we pass the transcations.
3. in call transaction ,we can call any number of transacions using call transaction <tcode>.
but now which method to use?
the scenario is when the first one is successfull, update the second one.
session method is clearly not possible as bdc_insert does not return sy-subrc = 0 which means succefull.
so, we need to go in this situation for call transaction method only
like wise depending on the situation we need to switch over.
if huge number of data is there to update we generally prefer session method rather than call transaction.
Bluesky
