How To Fix AD434 - Key is already defined; field & cannot be in the key

SAP Error Message - Details

• Message type: E = Error

• Message class: AD - Data Dictionary application messages

• Message number: 434

• Message text: Key is already defined; field & cannot be in the key

What causes this issue?

When defining table fields, you added further key fields at the end
after entering a block of key fields followed by a block of non-key
fields.
All the key fields of a table must be in a block at the beginning of
the table.

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?

All key fields in a table should be entered in a single block.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message AD434 - Key is already defined; field & cannot be in the key ?

  The SAP error message AD434 indicates that there is an attempt to define a key field in a database table or structure that is already defined as part of the key. This typically occurs when you are trying to add a field to a key that is already included in the key definition.
  Cause:
  
  Duplicate Key Definition: The field you are trying to add is already part of the key for the table or structure.
  Incorrect Table/Structure Design: The design of the table or structure may not be aligned with the intended key fields.
  Modification of Existing Structures: If you are modifying an existing table or structure, you may inadvertently try to redefine a key field.
  
  Solution:
  
  Check Key Definition: Review the key definition of the table or structure in transaction SE11 (Data Dictionary). Ensure that the field you are trying to add is not already included in the key.
  Modify Key Fields: If you need to change the key fields, you may need to remove the field from the key definition before adding it again, or adjust your design to avoid duplication.
  Use Unique Fields: If you need to add a new field to the key, ensure that it is unique and not already part of the existing key.
  Consult Documentation: Refer to SAP documentation or guidelines for defining keys in database tables to ensure compliance with best practices.
  
  Related Information:
  
  Transaction Codes: Use SE11 to view and modify table definitions, and SE14 for database utility operations.
  Data Dictionary: Familiarize yourself with the SAP Data Dictionary concepts, especially regarding primary keys and unique constraints.
  SAP Notes: Check for any relevant SAP Notes that might address specific issues or provide additional guidance related to key definitions.
  
  If the problem persists after checking the above points, consider reaching out to your SAP Basis or ABAP development team for further assistance.