How To Fix SDDL_PARSER_MSG257 - Two target fields cannot be compared in the composition definition

SAP Error Message - Details

• Message type: E = Error

• Message class: SDDL_PARSER_MSG - Message Class for DDL Parser

• Message number: 257

• Message text: Two target fields cannot be compared in the composition definition

What causes this issue?

It is not possible to compare two fields of the child entity in the ON
condition of a composition definition.

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?

The comparison must contain a key field of the parent entity.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message SDDL_PARSER_MSG257 - Two target fields cannot be compared in the composition definition ?

  The SAP error message SDDL_PARSER_MSG257 indicates that there is an issue with the composition definition in your SAP system, specifically that two target fields cannot be compared. This typically occurs in the context of data modeling or when defining relationships between different data elements in SAP.
  Cause:
  The error usually arises due to one of the following reasons:
  
  Incompatible Data Types: The two target fields you are trying to compare may have incompatible data types. For example, one field might be a string while the other is a numeric type.
  Field Length Mismatch: The lengths of the fields being compared may not match, which can lead to issues during comparison.
  Incorrect Field Mapping: There may be a mistake in how the fields are mapped in the composition definition, leading to an invalid comparison.
  Missing or Incorrect Metadata: The metadata for the fields may not be correctly defined, causing the system to be unable to interpret the fields properly.
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Check Data Types: Verify that the data types of the two target fields are compatible. If they are not, you may need to convert one of the fields to match the other.
  
  
  Review Field Lengths: Ensure that the lengths of the fields being compared are compatible. If necessary, adjust the field lengths in the data model.
  
  
  Examine Field Mapping: Review the composition definition to ensure that the fields are correctly mapped. Make sure that you are comparing the correct fields and that they are intended to be compared.
  
  
  Validate Metadata: Check the metadata definitions for the fields involved. Ensure that they are correctly defined and that there are no discrepancies.
  
  
  Test with Sample Data: If possible, test the comparison with sample data to see if the issue persists. This can help identify if the problem is with specific data entries.
  
  
  Consult Documentation: Refer to SAP documentation or help resources for additional guidance on composition definitions and field comparisons.
  
  
  Seek Support: If the issue persists after trying the above steps, consider reaching out to SAP support or consulting with a technical expert who has experience with SAP data modeling.
  
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that might address this specific error or provide additional troubleshooting steps.
  SAP Community: Engage with the SAP Community forums to see if other users have encountered similar issues and what solutions they found effective.
  Training and Documentation: Review SAP training materials or documentation related to data modeling and composition definitions for best practices and guidelines.
  
  By following these steps, you should be able to identify and resolve the cause of the SDDL_PARSER_MSG257 error in your SAP system.