How To Fix D9748 - The logical key &1 cannot be changed subsequently

SAP Error Message - Details

• Message type: E = Error

• Message class: D9 - Environment Management System

• Message number: 748

• Message text: The logical key &1 cannot be changed subsequently

What causes this issue?

You attempted to subsequently change the logical key &V1&. This change
is not permitted for this object.

System Response

The SAP System rejects your processing.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message D9748 - The logical key &1 cannot be changed subsequently ?

  The SAP error message D9748, which states "The logical key &1 cannot be changed subsequently," typically occurs when there is an attempt to modify a key field in a database table that is defined as a logical key. Logical keys are used to uniquely identify records in a table, and once they are set, they cannot be changed to maintain data integrity.
  Cause:
  
  Attempting to Change a Key Field: The most common cause of this error is an attempt to change a field that is part of the logical key of a database table after it has been created or populated with data.
  Data Integrity Rules: SAP enforces strict data integrity rules, and changing a logical key could lead to inconsistencies in the database.
  Custom Development: If there is custom development or enhancements that try to modify the logical key fields, this error may arise.
  
  Solution:
  
  Review the Code: Check the code or transaction that is causing the error. Ensure that you are not trying to change a logical key field.
  Use Alternative Fields: If you need to change the data, consider using non-key fields or creating a new record with the desired values instead of modifying the existing one.
  Data Migration: If you need to change the logical key for a large number of records, consider data migration strategies where you create new records with the new keys and delete the old ones.
  Consult Documentation: Review the SAP documentation for the specific table or module you are working with to understand the implications of changing logical keys.
  Seek Help from SAP Support: If the issue persists and you cannot find a resolution, consider reaching out to SAP support for assistance.
  
  Related Information:
  
  Logical Keys in SAP: Understand the concept of logical keys in SAP and how they are used in various modules.
  Data Dictionary (SE11): Use transaction SE11 to view the structure of the table and identify which fields are defined as logical keys.
  Change Management: Implement proper change management practices to avoid unintentional modifications to key fields in the future.
  Testing: Always test changes in a development or quality assurance environment before applying them to production.
  
  By following these steps, you should be able to address the D9748 error effectively.