All About SAP BDC | Batch Data Communication
This tutorial will cover the following topics-
- Introduction to BDC.
- Method of Batch Input.
- Batch Data Procedures.
- Writing BDC programs.
- Creating Batch input Session.
- Batch Input Recording.
Introduction to Batch input
Batch input is typically used to transfer data from non-R/3 systems to R/3 systems or to transfer data between R/3 systems.
It is a data transfer technique that allows you to transfer datasets automatically to screens belonging to transactions, and thus to an SAP system. Batch input is controlled by a batch input session.
Batch input session
Groups a series of transaction calls together with input data and user actions . A batch input session can be used to execute a dialog transaction in batch input, where some or all the screens are processed by the session. Batch input sessions are stored in the database as database tables and can be used within a program as internal tables when accessing transactions.
Points to note
- BDI works by carrying out normal SAP transactions just as a user would but it execute the transaction automatically.All the screen validations and business logic validation will be done while using Batch Data Input.
- It is suitable for entering large amount of data.
- No manual interaction is required
Methods of Batch Input
SAP provide two basic methods for transferring legacy data in to the R/3 System.
- Classical Batch Input method.
- Call Transaction Method.
Classical Batch Input method
In this method an ABAP/4 program reads the external data to the SAP System and stores in a batch input session.
After creating the session, you can run the session to execute the SAP transaction in it.
This method uses the function modules BDC_ OPEN, BDC_INSERT and BDC_CLOSE
Batch Input Session can be process in 3 ways
- In the foreground
- In the background
- During processing, with error display
You should process batch input sessions in the foreground or using the error display if you want to test the data transfer.
If you want to execute the data transfer or test its performance, you should process the sessions in the background.
Points to note about Classical Batch Input method
- Asynchronous processing
- Transfer data for multiple transactions.
- Synchronous database update.
- A batch input process log is generated for each session.
- Session cannot be generated in parallel.
Call Transaction Method.
In this method ABAP/4 program uses CALL TRANSACTION USING statement to run an SAP transaction.
Entire batch input process takes place online in the program
Points to Note:
- Faster processing of data
- Synchronous processing
- Transfer data for a single transaction.
- No batch input processing log is generated.
Batch Input Procedures
You will typically observe the following sequence of steps to develop Batch Input for your organization
- Analysis of the legacy data. Determine how the data to be transferred is to be mapped in to the SAP Structure. Also take note of necessary data type or data length conversions.
- Generate SAP data structures for using in export programs.
- Export the data in to a sequential file. Note that character format is required by predefined SAP batch input programs.
- If the SAP supplied BDC programs are not used, code your own batch input program. Choose an appropriate batch input method according to the situation.
- Process the data and add it to the SAP System.
- Analyze the process log. For the CALL TRANSACTION method, where no proper log is created, use the messages collected by your program.
- From the results of the process analysis, correct and reprocess the erroneous data.
Writing BDC program
You may observe the following process to write your BDC program
- Analyze the transaction(s) to process batch input data.
- Decide on the batch input method to use.
- Read data from a sequential file
- Perform data conversion or error checking.
- Storing the data in the batch input structure,BDCDATA.
- Generate a batch input session for classical batch input,or process the data directly with CALL TRANSACTION USING statement.
Batch Input Data Structure
Declaration of batch input data structure
DATA : BEGIN OF < bdc table> OCCURS <occurs parameters>. INCLUDE STRUCTURE BDCDATA. DATA:END OF <bdc table>.
|DYNBEGIN||CHAR||1||Starting a dynpro|
The order of fields within the data for a particular screen is not of any significance
Points to Note
- While populating the BDC Data make sure that you take into consideration the user settings. This is specially relevant for filling fields which involves numbers ( Like quantity, amount ). It is the user setting which decides on what is the grouping character for numbers E.g.: A number fifty thousand can be written as 50,000.00 or 50.000,00 based on the user setting.
- Condense the FVAL field for amount and quantity fields so that they are left aligned.
- Note that all the fields that you are populating through BDC should be treated as character type fields while populating the BDC Data table.
- In some screens when you are populating values in a table control using BDC you have to note how many number of rows are present on a default size of the screen and code for as many rows. If you have to populate more rows then you have to code for "Page down" functionality as you would do when you are populating the table control manually.
- Number of lines that would appear in the above scenario will differ based on the screen size that the user uses. So always code for standard screen size and make your BDC work always in standard screen size irrespective of what the user keeps his screen size as.
Creating Batch Input Session
- Open the batch input session session using function module BDC_OPEN_GROUP.
For each transaction in the session:
- Fill the BDCDATA with values for all screens and fields processed in the transaction.
- Transfer the transaction to the session with BDC_INSERT.
- Close the batch input session with BDC_CLOSE_GROUP
Batch Input Recorder
Batch input recorder (System > Services > Batch input > Recorder) records transactions which are manually entered and creates a batch input session which can be executed later using SM35.
- Begin the batch input recorder by selecting the Recording pushbutton from the batch input initial screen.
- The recording name is a user defined name and can match the batch input session name which can be created from the recording.
- Enter a SAP transaction and begin posting the transaction.
- After you have completed posting a SAP transaction you either choose Get Transaction and Save to end the recording or Next Transaction and post another transaction.
- Once you have saved the recording you can create a batch input session from the recording and/or generate a batch input program from the recording.
- The batch input session you created can now be analyzed just like any other batch input session.
- The program which is generated by the function of the batch input recorder is a powerful tool for the data interface programmer. It provides a solid base which can then be altered according to customer requirements.