Why BDC when we can do the same with Bapi's

Question

Hiii
Plz tell me why BDC when we can do the same with Bapi...
plz list out the differences clearly
Thanks & Regards
krishna

Answer 1

If the same functionality can be achieved by BAPI then we generally go for BAPI instead of BDC. The main reason is that the screen no can change in the next version and in that case the BDC code will not work. But if no BAPI is available then we go for BDC.
Sometimes we need to handle a large amount of data in BDC/BAPI in which it is not preferable to use 'CALL TRANSACTION' command. If the corresponding BAPI internally use 'CALL TRANSACTION'  command. Then instead of that BAPI we create a BDC with SESSION METHOD.
Ex: IDOC_INPUT_ORDERS internally use CALL TRANSACTION. So if we need to use a large amount of data we create a BDC with session method instead of using IDOC_INPUT_ORDERS.