BDC & LSMW

1	What is BDC.
	BDC means Batch Data Communication and is used to upload mass data at a given time.
2	What are the methods for uploading data.
	a. Session method. b. Call Transaction method. c. Direct input method.
3.	How do we make a recording.
	Through SHDB.
4	What is a typical BDC structure.
	a. Program name b. Screen No c. Start of screen d. Field name e. Field value
5	What should be internal table type used for uploading data to BDC.
	Table should be of type BDCDATA.
6	What are the FM used for BDC.
	BDC_OPEN_GROUP BDC_INSERT BDC_CLOSE_GROUP
7	What thing(s) should we keep in mind while recording.
	We should make sure that all the mandatory fields are included in the recording, else BDC will fail.
8	How do we handle currency or quantity field in BDC.
	Use write statement with currency/quantity option.
9	Where is session stored.
	SM35.
10	What are the modes of executing a BDC.
	a. Fore ground. b. Back ground. c. Only error screen.
11	Are logs maintained in BDC.
	Yes.
12	Is a session stored after execution.
	It depends on the selection made by the user in FM BDC_OPEN_GROUP if he has selected the option of Keep = ‘X’ then session is stored else its deleted.
13	Can we generate programs from SHDB recording.
	Yes we can, Just select the recording and click new program.
14	What is the difference between a call transaction and session method.
	a. No logs are created in call transaction method. b. No session is created here. c. Need to execute records one by one in call transaction.
15	What type of internal table should be created for call transaction.
	BDCDATA.
16	How can we see error messages during call transaction.
	Create a internal table of type BDCMSGCOLL and use this in call transaction, this will return the messages during the call transaction.
17	What is a synchronous and asynchronous methos.
	Synchronous method means simultaneous execution while asynchronous means at later stage the execution takes place.
18	Is BDC synchronous or asynchronous.
	Session methods can be both Synchronous and Asynchronous but call transaction is always synchronous

LSMW

1	What is LSMW.
	Legacy System Migration Workbench.
2	What is the difference between LSMW and BDC.
	a. LSMW has least coding. b. Very simple c. Has got number of standard recordings. d. We can group similar recordings forming Projects and Sub-Projects. e. Documentation can be provided at every stage. f. We can insert additional coding and rules in LSMW. g. To run LSMW user does not need to have ABAP knowledge.
3.	What are different import types for data uploading in LSMW.
	a. Standard Input. b. Batch Input. c. Bapi d. IDOC
4	Can we upload a given range of records say from 10-80.
	Yes we can.

Difference between BDC and LSMW

BDC	LSMW
1. Lots of coding	1. Minimal coding almost nil
2. Data can be uploaded through recording only	2. Has 4 methods for uploading data a. Standard b. Recording c. Bapis d. Idoc
3. Uploading cannot be done for specific set of records.	3. Uploading can be done for specific set of records.
4. We cannot group logically related BDC	4. We can group the LSMW as project /sub project / objects
5. Does require programming knowledge	5. Does not require programming knowledge