How To Fix USMD1620 - Data model &1, entity type &2: Attribute &3 is a key field

SAP Error Message - Details

• Message type: E = Error

• Message class: USMD1 - Datenmodel

• Message number: 620

• Message text: Data model &1, entity type &2: Attribute &3 is a key field

What causes this issue?

The attribute &V3& was assigned to entity type &V2& in model &V1&.
However, the entity type already has a key field with the same name.
Within an entity type, no attribute can have the same name as a key
field.

System Response

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

The model cannot be activated.
ELSE
The model cannot be saved.
ENDIF

How to fix this error?

Enter a different name for the attribute.

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 USMD1620 - Data model &1, entity type &2: Attribute &3 is a key field ?

  The SAP error message USMD1620 typically occurs in the context of SAP Master Data Governance (MDG) when there is an issue related to the data model configuration, specifically concerning key fields in an entity type. Here’s a breakdown of the cause, potential solutions, and related information for this error message:
  Cause:
  The error message indicates that there is an attempt to perform an operation (such as creating, updating, or deleting) on an attribute that is defined as a key field in the data model. Key fields are essential for uniquely identifying records in a database table, and certain operations may not be allowed on these fields due to their critical role in maintaining data integrity.
  Solution:
  
  
  Review Data Model Configuration:
  
  Check the data model configuration in the SAP MDG system. Ensure that the attributes defined as key fields are correctly set up and that any operations you are trying to perform are valid for those fields.
  
  
  
  Avoid Modifying Key Fields:
  
  If you are trying to modify a key field, consider whether this is necessary. Key fields should generally remain constant to maintain data integrity. If a change is required, it may be necessary to create a new record instead of modifying the existing one.
  
  
  
  Check for Custom Logic:
  
  If there is custom logic (e.g., BAdIs, user exits) that interacts with the key fields, review this logic to ensure it does not inadvertently attempt to modify key fields inappropriately.
  
  
  
  Consult Documentation:
  
  Refer to the SAP documentation for the specific data model and entity type you are working with. This can provide insights into the expected behavior and constraints related to key fields.
  
  
  
  Error Handling:
  
  Implement error handling in your application logic to gracefully manage situations where operations on key fields are attempted.
  
  
  
  Testing:
  
  Conduct thorough testing in a development or quality assurance environment to replicate the issue and validate that the changes made resolve the error.
  
  
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that may address this specific error message or provide additional context on handling key fields in MDG.
  SAP Community: Engage with the SAP Community forums to see if other users have encountered similar issues and what solutions they have found.
  Training and Documentation: Consider additional training on SAP MDG and data modeling concepts to better understand the implications of key fields and data integrity.
  
  By following these steps, you should be able to address the USMD1620 error and ensure that your data model operates correctly within the SAP MDG framework.