How To Fix ACM_SYNTAX026 - No unique key was defined for entity &1

ACM_SYNTAX026 - Overview

• Message type: E = Error

• Message class: ACM_SYNTAX - ACM: DCL Syntax Error Messages

• Message number: 026

• Message text: No unique key was defined for entity &1

What causes this issue?

For an entity no unique key was defined in its DDL.
A user-defined unique key is a mandatory prerequisite to create a DCL
for a CDS entity.

System Response

Currently, this is just a warning. The DCL role can be created and
activated nevertheless.
But in the near future, a missing unique key will result in an error!

How to fix this error?

Please specify a unique key (with one or more key fields) for this
entity in its DDL source document by using the keyword: KEY.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.

ACM_SYNTAX026 - Details

• The SAP error message ACM_SYNTAX026 indicates that there is no unique key defined for a specific entity in the system. This error typically arises in the context of data modeling or when working with certain applications that require a unique identifier for records.
  
  Cause:
  
  Missing Unique Key Definition: The entity in question does not have a unique key defined, which is necessary for the system to identify records uniquely.
  Data Model Issues: The data model may not have been properly configured, leading to the absence of a unique key.
  Configuration Errors: There may be errors in the configuration of the application or module that is trying to access the entity.
  
  
  Solution:
  
  
  Define a Unique Key:
  
  Go to the relevant data model or entity configuration in the SAP system.
  Identify the fields that can serve as a unique identifier for the records.
  Define a unique key by selecting the appropriate fields and marking them as unique.
  
  
  
  Check Data Model Configuration:
  
  Review the