Writing Data Conversion Programs 

The data conversion program is responsible for the following tasks:

●     Converting the data that is to be transferred into the SAP system as required by the SAP data structure or transactions that you are using.

If you are using an SAP batch input standard program, you must generate the data structure from the SAP standard data structure (see generating an SAP data structure).

If you develop your own batch input program, the data structure is determined by the SAP system when the program is generated. Generate a test file from the recording and align the format of your conversion program with the format of the test file.

A conversion may be necessary for data type and length  data type and length. The data type required by all standard SAP batch input programs is C, character data. You can find the required field lengths either in your analysis of the data declaration structure of the generated batch input program or in the data structures that you generate.

●     The data is exported in SAP format to a sequential file. The batch input program in the SAP system reads the data in from this file.

Process flow

The tasks involved in writing a data transfer program are shown in the diagram and list below.

...

       1.      Analyze the structure of your existing data and specify the conversions that are required to fill the SAP data structures.

If necessary, generate the SAP data structure in code form and insert it into your program.

       2.      This is only possible if the SAP data structure is an ABAP Dictionary object (structure, table).

Fill the structure with data. If you do not want to assign a value to a field in the structure, use the NODATA character. Execute any conversions conversions and error checks that may be required.

       3.      Write the sequential file that is typically required for making the data available to the data transfer program in the SAP system.

For SAP data transfer standard programs, all data must have the character format.