How To Fix WER281 - The key field must be a simple data compoment

SAP Error Message - Details

• Message type: E = Error

• Message class: WER - Messages for the package WER

• Message number: 281

• Message text: The key field must be a simple data compoment

Self-Explanatory Message

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• What is the cause and solution for SAP error message WER281 - The key field must be a simple data compoment ?

  SAP Error Message:
  
  WER281 - The key field must be a simple data component
  
  Cause:
  This error occurs when you define a key field in a table or structure, but the key field is not a simple data component. In SAP ABAP Dictionary, key fields must be elementary data types (simple data components), such as CHAR, NUMC, INT, DEC, etc. They cannot be complex types like structures, table types, or reference types.
  For example, if you try to use a structure or a deep type as a key field in a transparent table or a structure, the system will raise this error.
  
  Explanation:
  
  Key fields uniquely identify records in a table.
  SAP requires key fields to be simple, atomic data types to ensure uniqueness and proper indexing.
  Complex types (structures, table types) cannot be used as keys because they do not represent a single atomic value.
  
  
  Solution:
  
  Check the data type of the field you are trying to use as a key.
  Ensure that the key field is a simple data element (elementary type).
  If the field is a structure or a complex type, replace it with one or more simple fields that uniquely identify the record.
  If you need to use multiple fields as a key, define them individually as simple data components and mark them as key fields.
  
  
  Steps to fix:
  
  Go to the ABAP Dictionary (transaction SE11).
  Open the table or structure where the error occurs.
  Identify the key fields.
  Verify the data type of each key field.
  Change any complex data type key fields to simple data elements.
  Save and activate the object.
  
  
  Related Information:
  
  Key fields must be elementary data types.
  Composite keys are allowed but each key field must be simple.
  This error is common when copying or creating tables/structures from existing complex types.
  Refer to SAP documentation on ABAP Dictionary and Table Keys for more details.
  
  
  Summary:
  
  WER281 occurs because a key field is not a simple data component. To resolve it, ensure all key fields are elementary data types, not structures or complex types.