Rfcabapexception error while querying a number of columns using RFC_READ_TABLE in SAP

The Rfcabapexception error occurs when using RFC_READ_TABLE in SAP, but it is not because of the number of columns being queried. The actual issue is the total size of the fields you are querying, which should not exceed 512 bytes.

Why This Error Occurs

For RFC communication, complex data types like DATA or STANDARD tables are not supported. Therefore, the RFC_READ_TABLE function module must convert the data into a generic format, and the data is transferred as a series of lines. It is the size of these table lines that matters most.

The size cannot exceed 512 characters. If the size is greater than 512 characters, the module throws a Rfcabapexception exception with a short dump.

Checking the Error

The dump can be checked using transaction ST22 in SAP. This transaction displays runtime errors and provides detailed information about what caused the exception.

Solutions

When you encounter this error, you will need to break the table vertically. This means splitting your query into multiple calls, selecting fewer columns in each call to stay within the 512-byte limit.

Example Approach

Instead of querying all columns at once ?

" Instead of this (may exceed 512 bytes):
CALL FUNCTION 'RFC_READ_TABLE'
  EXPORTING
    query_table = 'MARA'
    fields = 'MATNR,MBRSH,MTART,MATKL,BISMT,MEINS,BRGEW,NTGEW,GEWEI'

Split into multiple calls ?

" First call - basic fields
CALL FUNCTION 'RFC_READ_TABLE'
  EXPORTING
    query_table = 'MARA'
    fields = 'MATNR,MBRSH,MTART,MATKL'

" Second call - additional fields  
CALL FUNCTION 'RFC_READ_TABLE'
  EXPORTING
    query_table = 'MARA'
    fields = 'MATNR,BISMT,MEINS,BRGEW,NTGEW,GEWEI'

Additional Issues

There can also be issues if the fields you are querying cannot be converted to character format or if the fields have a variable length. In such cases, consider using alternative approaches like creating custom RFCs or using different SAP integration methods.

Conclusion

The Rfcabapexception error in RFC_READ_TABLE is caused by exceeding the 512-byte limit for field sizes, not the number of columns. The solution is to split your queries vertically to stay within this limit.