How To Fix CNV_00001257 - Target field &1 is mapped by multiple field mappings of source table &1

SAP Error Message - Details

• Message type: E = Error

• Message class: CNV_00001 - Message class for CWB settings maintenance programs

• Message number: 257

• Message text: Target field &1 is mapped by multiple field mappings of source table &1

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message CNV_00001257 - Target field &1 is mapped by multiple field mappings of source table &1 ?

  The SAP error message CNV_00001257 indicates that there is a conflict in the data mapping during a data migration or conversion process. Specifically, it means that the target field in the target table is being mapped by multiple source fields from the source table, which can lead to ambiguity in the data transfer process.
  Cause:
  The error typically arises in scenarios where:
  
  Multiple source fields are trying to populate the same target field, which is not allowed.
  There may be an incorrect configuration in the mapping settings, leading to overlapping mappings.
  The data model may have changed, and the mappings have not been updated accordingly.
  
  Solution:
  To resolve this error, you can follow these steps:
  
  
  Review the Mapping Configuration:
  
  Check the mapping configuration for the specific target field mentioned in the error message.
  Identify all the source fields that are mapped to the target field.
  
  
  
  Eliminate Redundant Mappings:
  
  Determine which source field should be the primary source for the target field.
  Remove or adjust the mappings for the other source fields that are conflicting.
  
  
  
  Update the Mapping Logic:
  
  If necessary, modify the logic to ensure that only one source field is mapped to the target field.
  If multiple source fields need to contribute to the target field, consider creating a new target field or using a transformation logic to combine the values.
  
  
  
  Test the Changes:
  
  After making the necessary adjustments, run a test migration to ensure that the error is resolved and that the data is being transferred correctly.
  
  
  
  Documentation:
  
  Document the changes made to the mapping for future reference and to avoid similar issues.
  
  
  
  Related Information:
  
  Transaction Codes: You may need to use transaction codes like LTMC (Legacy Transfer Migration Cockpit) or LTMOM (Migration Object Modeler) to access and modify the mapping settings.
  SAP Notes: Check for any relevant SAP Notes that may provide additional guidance or updates related to this error.
  Data Migration Best Practices: Familiarize yourself with best practices for data migration in SAP to avoid similar issues in the future.
  
  By following these steps, you should be able to resolve the CNV_00001257 error and ensure a smooth data migration process.