SESSION METHOD IN SAP ABAP. 

Differences between call transaction and session method.

In call transaction updation is immediate but in session method updation is not immediate.

In call transaction user has to handle errors but in session system handles the errors.

In call transaction updation can be synchronous or asynchronous or local but in session method updation by default synchronous.

Call transaction returns sy-subrc value but session will not return sy-subrc value.

In session method the data will be stored intermediately in session. After processing the session only the data will be moved into data base. For processing the session the T-code is SM35.

SESSION:- It is an intermediate memory area where data with flow logic is stored. It is intermediate between internal table and data base table. A session can not be processed on the date on which it is created. A session can not be processed if it is processed successfully. If session is having error it can be processed any number of times.

In session method we have to use 3 function modules.

BDC_OPEN_GROUP

BDC_INSERT

BDC_CLOSE_GROUP

BDC_OPEN_GROUP: -  This function module is used to create a session with particular name.

BDC_INSERT:-  This function module is used to move flow logic and data into session. This function module should be called between the loop and endloop after recording steps.

BDC_CLOSE_GROUP:- This function module should be used to close the session. If this function module is not used the session will be created but we cant process the session.