How To Fix DT231 - Field name & is reserved (Structure cannot be used as append in DB table)

SAP Error Message - Details

• Message type: E = Error

• Message class: DT - Table activation (incl. indexes)

• Message number: 231

• Message text: Field name & is reserved (Structure cannot be used as append in DB table)

What causes this issue?

In an append structure, you use a field name which is reserved by the
database.

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?

This will only cause an error if you use the structure as an append
structure in a database table.
You may not use the table as an append structure in a new database
table and also may not newly add it as an append structure to a
database table which is already active.
The table activation program rejects this because use of this database
table could cause errors, depending on the database system.
A warning is output for tables which are already active and which have
such an append structure.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message DT231 - Field name & is reserved (Structure cannot be used as append in DB table) ?

  The SAP error message DT231 indicates that a field name you are trying to use in a structure is reserved and cannot be used as an append in a database table. This typically occurs when you are trying to enhance a database table with a structure that contains field names that are either reserved keywords in SAP or already exist in the database table.
  Cause:
  
  Reserved Field Names: The field name you are trying to use is a reserved keyword in SAP. Certain names are predefined and cannot be used for custom fields.
  Existing Field Names: The field name already exists in the database table you are trying to append to. This can happen if you are trying to add a field that has the same name as an existing field in the table.
  Naming Conventions: SAP has specific naming conventions and restrictions for field names, and using names that do not comply with these conventions can lead to this error.
  
  Solution:
  
  Change Field Name: Modify the field name in your structure to something that is not reserved and does not conflict with existing field names in the database table. Use a prefix or suffix to differentiate your custom fields.
  Check Reserved Keywords: Refer to the SAP documentation or the ABAP Dictionary to check for reserved keywords and ensure that your field names do not conflict with them.
  Use Unique Names: Ensure that the names you choose for your fields are unique within the context of the database table and do not match any existing fields.
  Recreate Structure: If necessary, recreate the structure with the corrected field names and attempt to append it to the database table again.
  
  Related Information:
  
  ABAP Dictionary: You can check the ABAP Dictionary (transaction SE11) for existing fields in the database table and to see the list of reserved keywords.
  Naming Conventions: Familiarize yourself with SAP's naming conventions for custom fields and structures to avoid similar issues in the future.
  SAP Notes: Check for any relevant SAP Notes that might provide additional guidance or updates regarding this error message.
  
  By following these steps, you should be able to resolve the DT231 error and successfully append your structure to the database table.