How To Fix DT454 - Field &: Preceding & field cannot be a key field

DT454 - Overview

• Message type: E = Error

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

• Message number: 454

• Message text: Field &: Preceding & field cannot be a key field

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

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Smart SAP Assistant

• What is the cause and solution for SAP error message DT454 - Field &: Preceding & field cannot be a key field ?

  The SAP error message DT454 ("Field &: Preceding & field cannot be a key field") typically occurs in the context of data dictionary definitions, particularly when defining database tables or structures in the ABAP Dictionary (SE11). This error indicates that there is an issue with the key fields defined for a table or structure.
  
  Cause:
  The error arises when you attempt to define a field as a key field that is not allowed to be a key field based on its position or the context of the preceding field. This can happen due to several reasons:
  
  Field Positioning: The field you are trying to set as a key field is positioned after another field that is already defined as a key field, which is not allowed.
  Data Type Restrictions: Certain data types or field attributes may not be allowed as key fields.
  Table Structure: The overall structure of the table may not support the key