<b>SESSION METHOD</b>
About Session method
In this method you transfer data from internal table to database table through sessions.
In this method, an ABAP/4 program reads the external data that is to be entered in the SAP System and stores the data in session. A session stores the actions that are required to enter your data using normal SAP transaction i.e., Data is transferred to session which in turn transfers data to database table.
Session is intermediate step between internal table and database table. Data along with its action is stored in session i.e., data for screen fields, to which screen it is passed, the program name behind it, and how the next screen is processed.
When the program has finished generating the session, you can run the session to execute the SAP transactions in it. You can either explicitly start and monitor a session or have the session run in the background processing system.
Unless session is processed, the data is not transferred to database table.
<b>BDC_OPEN_GROUP</b>
You create the session through program by BDC_OPEN_GROUP function.
Parameters to this function are:
• User Name: User name
• Group: Name of the session
• Lock Date: The date on which you want to process the session.
• Keep: This parameter is passed as ‘X’ when you want to retain session after
processing it or ‘ ‘ to delete it after processing.
<b>BDC_INSERT</b>
This function creates the session & data is transferred to Session.
Parameters to this function are:
• Tcode: Transaction Name
• Dynprotab: BDC Data
<b>BDC_CLOSE_GROUP</b>
This function closes the BDC Group. No Parameters.
Some additional information for session processing
When the session is generated using the KEEP option within the BDC_OPEN_GROUP, the system always keeps the sessions in the queue, whether it has been processed successfully or not.
However, if the session is processed, you have to delete it manually. When session processing is completed successfully while KEEP option was not set, it will be removed automatically from the session queue. Log is not removed for that session.
If the batch-input session is terminated with errors, then it appears in the list of INCORRECT session and it can be processed again. To correct incorrect session, you can analyze the session. The Analysis function allows to determine which screen and value has produced the error. If you find small errors in data, you can correct them interactively, otherwise you need to modify batch input program, which has generated the session or many times even the data file.
<b>CALL TRANSACTION</b>
About CALL TRANSACTION
A technique similar to SESSION method, while batch input is a two-step procedure, Call Transaction does both steps online, one after the other. In this method, you call a transaction from your program by
Call transaction <tcode> using <BDCTAB>
Mode <A/N/E>
Update <S/A>
Messages into <MSGTAB>.
Parameter – 1 is transaction code.
Parameter – 2 is name of BDCTAB table.
Parameter – 3 here you are specifying mode in which you execute transaction
A is all screen mode. All the screen of transaction are displayed.
N is no screen mode. No screen is displayed when you execute the transaction.
E is error screen. Only those screens are displayed wherein you have error record.
Parameter – 4 here you are specifying update type by which database table is updated.
S is for Synchronous update in which if you change data of one table then all the related Tables gets updated. And sy-subrc is returned i.e., sy-subrc is returned for once and all.
A is for Asynchronous update. When you change data of one table, the sy-subrc is returned. And then updating of other affected tables takes place. So if system fails to update other tables, still sy-subrc returned is 0 (i.e., when first table gets updated).
Parameter – 5 when you update database table, operation is either successful or unsuccessful or operation is successful with some warning. These messages are stored in internal table, which you specify along with MESSAGE statement. This internal table should be declared like BDCMSGCOLL, a structure available in ABAP/4. It contains the following fields:
1. Tcode: Transaction code
2. Dyname: Batch point module name
3. Dynumb: Batch input Dyn number
4. Msgtyp: Batch input message type (A/E/W/I/S)
5. Msgspra: Batch input Lang, id of message
6. Msgid: Message id
7. MsgvN: Message variables (N = 1 - 4)
For each entry, which is updated in database, table message is available in BDCMSGCOLL. As BDCMSGCOLL is structure, you need to declare a internal table which can contain multiple records (unlike structure).
Steps for CALL TRANSACTION method
1. Internal table for the data (structure similar to your local file)
2. BDCTAB like BDCDATA
3. UPLOAD or WS_UPLOAD function to upload the data from local file to itab. (Considering file is local file)
4. Loop at itab.
Populate BDCTAB table.
Call transaction <tcode> using <BDCTAB>
Mode <A/N/E>
Update <S/A>.
Refresh BDCTAB.
Endloop.
(To populate BDCTAB, You need to transfer each and every field)
<b>The major differences between Session method and Call transaction are as follows:</b>
SESSION METHOD CALL TRANSACTION
1. Data is not updated in database table unless Session is processed. Immediate updation in database table.
2. No sy-subrc is returned. Sy-subrc is returned.
3. Error log is created for error records. Errors need to be handled explicitly
4. Updation in database table is always synchronous Updation in database table can be synchronous Or Asynchronous.
Regards,
Santosh
Bluesky
