How To Fix SDDL_PARSER_MSG123 - Union clauses in basis view & and extend & do not match

SAP Error Message - Details

• Message type: E = Error

• Message class: SDDL_PARSER_MSG - Message Class for DDL Parser

• Message number: 123

• Message text: Union clauses in basis view & and extend & do not match

What causes this issue?

If a CDS view contains a UNION clause, identical UNION clauses must be
used in a corresponding CDS view extend. This means, type (UNION or
UNION ALL) and number of linked elements must be the same.

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?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message SDDL_PARSER_MSG123 - Union clauses in basis view & and extend & do not match ?

  The SAP error message SDDL_PARSER_MSG123 indicates that there is a mismatch between the union clauses in a basis view and an extended view in the context of SAP's Semantic Data Definition Language (SDDL). This typically occurs when you are trying to create or modify a CDS (Core Data Services) view that involves unions, and the structure of the union clauses does not align correctly.
  Cause:
  
  Mismatched Fields: The fields defined in the union clauses of the basis view and the extended view do not match in terms of data types, names, or the number of fields.
  Inconsistent Annotations: Annotations or metadata associated with the fields in the basis and extended views may not be consistent.
  Incorrect Union Logic: The logic used to create the union in either the basis or extended view may be incorrect, leading to discrepancies.
  
  Solution:
  
  Check Field Definitions: Ensure that the fields in the union clauses of both the basis and extended views match in terms of:
  
  Data types
  Field names
  Number of fields included in the union
  
  
  Review Annotations: Verify that any annotations applied to the fields in both views are consistent and correctly defined.
  Align Union Logic: Make sure that the logic used to create the union in both views is aligned. If you are adding or modifying fields, ensure that the changes are reflected in both views.
  Testing: After making the necessary adjustments, test the views to ensure that the error is resolved and that the views function as expected.
  
  Related Information:
  
  CDS Views: Core Data Services (CDS) views are a way to define semantically rich data models in SAP. Understanding how to create and extend these views is crucial for effective data modeling.
  SAP Documentation: Refer to the official SAP documentation for detailed guidelines on creating and managing CDS views, including best practices for unions and extensions.
  Debugging Tools: Utilize SAP's debugging tools to trace the error and identify the specific lines of code or definitions causing the issue.
  
  By following these steps, you should be able to resolve the SDDL_PARSER_MSG123 error and ensure that your CDS views are correctly defined and functional.