How To Fix SDDL_PARSER_MSG398 - Column "&2" in target entity "&1" cannot be a key field

SAP Error Message - Details

• Message type: E = Error

• Message class: SDDL_PARSER_MSG - Message Class for DDL Parser

• Message number: 398

• Message text: Column "&2" in target entity "&1" cannot be a key field

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

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Smart SAP Assistant

• What is the cause and solution for SAP error message SDDL_PARSER_MSG398 - Column "&2" in target entity "&1" cannot be a key field ?

  The SAP error message SDDL_PARSER_MSG398 indicates that there is an issue with the definition of a key field in a target entity within the SAP system. Specifically, the error states that the column (field) specified cannot be designated as a key field for the target entity.
  Cause:
  
  
  Invalid Key Field Definition: The column you are trying to set as a key field may not meet the requirements for key fields in the context of the target entity. This could be due to:
  
  The column being non-unique.
  The column being nullable (key fields typically must be non-nullable).
  The column type not being suitable for a key field (e.g., it may not be a primitive type).
  
  
  
  Entity Configuration Issues: The target entity may have specific constraints or configurations that prevent certain columns from being used as key fields.
  
  
  Data Model Constraints: The underlying data model may impose restrictions on which fields can be used as keys based on relationships with other entities or tables.
  
  
  Solution:
  
  
  Review Key Field Requirements: Check the requirements for key fields in the target entity. Ensure that the column you are trying to set as a key meets all necessary criteria (e.g., uniqueness, non-nullability).
  
  
  Modify the Column Definition: If possible, modify the column definition to ensure it can be used as a key field. This may involve:
  
  Changing the column to be non-nullable.
  Ensuring that the column has unique values.
  
  
  
  Check Entity Configuration: Review the configuration of the target entity to ensure that it allows the specified column to be a key field. You may need to adjust the entity's configuration or choose a different column that meets the criteria.
  
  
  Consult Documentation: Refer to SAP documentation or guidelines related to the specific module or functionality you are working with. This can provide insights into the constraints and requirements for key fields.
  
  
  Testing: After making changes, test the configuration to ensure that the error is resolved and that the target entity behaves as expected.
  
  
  Related Information:
  
  SAP Notes and Knowledge Base Articles: Check for any relevant SAP Notes or KBA (Knowledge Base Articles) that may address this specific error or provide additional context.
  SAP Community: Engage with the SAP Community forums to see if other users have encountered similar issues and what solutions they have found.
  Data Modeling Best Practices: Familiarize yourself with best practices for data modeling in SAP, particularly regarding entity relationships and key field definitions.
  
  By following these steps, you should be able to identify the cause of the error and implement a solution to resolve it.