How To Fix D0102 - Field & does not have a preceding length field of type &

SAP Error Message - Details

• Message type: E = Error

• Message class: D0 - Machine-level ABAP/4 Dictionary texts (e.g. debugging)

• Message number: 102

• Message text: Field & does not have a preceding length field of type &

What causes this issue?

A transparent table may contain only one field of data type LCHR or
LRAW. This field must always be at the end of the table. A length field
of a certain data type must always precede this field.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Insert a length field of the required type before the field of type
LCHR or LRAW or change the type of the length field to the required data
type. Further information about the length field and its type can be
found in the ABAP/4 Dictionary manual.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message D0102 - Field & does not have a preceding length field of type & ?

  The SAP error message D0102, which states "Field & does not have a preceding length field of type &," typically occurs in the context of data structures, particularly when dealing with internal tables or structures in ABAP (Advanced Business Application Programming). This error indicates that a field in a structure or table is expected to have a preceding length field, but it does not.
  Cause:
  
  
  Incorrect Structure Definition: The structure or table definition may be missing a length field for a variable-length field. In ABAP, when defining a structure that includes variable-length fields (like strings), a preceding length field is required to specify the length of the variable-length field.
  
  
  Data Type Mismatch: The field types may not be compatible, or the structure may not be defined correctly according to the expected data types.
  
  
  Legacy Code: If you are working with legacy code or code generated by tools, it may not conform to the current standards or practices, leading to this error.
  
  
  Solution:
  
  
  Check Structure Definition: Review the definition of the structure or internal table where the error occurs. Ensure that any variable-length fields (like STRING or XSTRING) have a corresponding length field defined before them.
  Example:
  TYPES: BEGIN OF my_structure,
           length_field TYPE i,  " Length field
           variable_field TYPE string,  " Variable-length field
         END OF my_structure.
  
  
  Modify the Data Structure: If you find that a length field is missing, add it to the structure definition. Ensure that the length field is of the appropriate type (usually an integer).
  
  
  Check for Compatibility: Ensure that the data types used in the structure are compatible with the operations you are performing. If you are using a legacy structure, consider refactoring it to align with current standards.
  
  
  Testing: After making changes, test the program or function module to ensure that the error is resolved and that the functionality works as expected.
  
  
  Related Information:
  
  ABAP Documentation: Refer to the official SAP ABAP documentation for guidelines on defining structures and internal tables.
  SAP Community: Engage with the SAP Community forums for insights and solutions from other developers who may have encountered similar issues.
  Debugging: Use the ABAP debugger to trace the execution and identify where the error is triggered, which can provide additional context for resolving the issue.
  
  By following these steps, you should be able to resolve the D0102 error and ensure that your ABAP code adheres to the necessary structure definitions.