How To Fix SADL_GW_DT_CDS001 - Join &1 is not allowed.

SAP Error Message - Details

• Message type: E = Error

• Message class: SADL_GW_DT_CDS - Messages CDS Checks

• Message number: 001

• Message text: Join &1 is not allowed.

What causes this issue?

A join is used in the SELECT statement in the consumption CDS view. This
is not allowed.

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?

Remove the join in the consumption CDS view. You can use an association
instead.

Procedure for System Administrators

Contact the corresponding developer of the CDS view to correct the
error.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message SADL_GW_DT_CDS001 - Join &1 is not allowed. ?

  The SAP error message SADL_GW_DT_CDS001 with the description "Join &1 is not allowed" typically occurs in the context of SAP Gateway and Core Data Services (CDS) views. This error indicates that there is an issue with the way joins are defined in your CDS view or the way the data is being accessed through the SAP Gateway.
  Cause:
  
  
  Invalid Join Definition: The join defined in the CDS view may not be valid due to various reasons, such as:
  
  The join is between incompatible data sources.
  The join condition is not properly defined.
  The join type is not supported in the context of the operation being performed.
  
  
  
  Restrictions on Joins: Certain joins may not be allowed due to the nature of the data sources involved. For example, joins between certain types of database tables or views may be restricted.
  
  
  Gateway Service Configuration: The error may also arise from the way the OData service is configured in the SAP Gateway. If the service is not properly set up to handle the joins defined in the CDS view, this error can occur.
  
  
  Solution:
  
  
  Review Join Conditions: Check the join conditions in your CDS view. Ensure that:
  
  The tables or views being joined are compatible.
  The join conditions are correctly specified.
  
  
  
  Simplify Joins: If possible, simplify the joins in your CDS view. Consider breaking down complex joins into simpler views or using associations instead of joins.
  
  
  Check Data Source Compatibility: Ensure that the data sources you are trying to join are compatible. For example, joining a database table with a view that has different semantics may lead to this error.
  
  
  Adjust OData Service Configuration: If the issue is related to the OData service, check the service configuration in the SAP Gateway:
  
  Ensure that the service is activated.
  Check the service metadata to ensure that it reflects the correct structure of the CDS view.
  
  
  
  Use Annotations: If applicable, use annotations in your CDS view to specify how the data should be handled, which may help in resolving the join issue.
  
  
  Debugging: Use transaction codes like SE11 (Data Dictionary) and SE80 (Object Navigator) to debug the CDS view and analyze the joins. You can also use transaction SADL to check the data access layer.
  
  
  Related Information:
  
  SAP Documentation: Refer to the official SAP documentation for Core Data Services and SAP Gateway for detailed guidelines on defining joins and configuring OData services.
  SAP Community: Engage with the SAP Community forums to see if others have encountered similar issues and to find potential solutions.
  SAP Notes: Check for any relevant SAP Notes that may address specific issues related to the error message.
  
  By following these steps, you should be able to identify the cause of the error and implement a solution to resolve it.