How To Fix SADL_GW_DT_CDS002 - Calculated field &1 is not allowed.

SADL_GW_DT_CDS002 - Overview

• Message type: E = Error

• Message class: SADL_GW_DT_CDS - Messages CDS Checks

• Message number: 002

• Message text: Calculated field &1 is not allowed.

What causes this issue?

In the CDS view (consumption view), a calculated field is defined:
e.g.: so.NetAmount + so.TaxAmount as GrossAmount
A field can only be calculated using a calculation exit.

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?

Create an ABAP class (CL_xxx_EXIT) which implements the interface
IF_SADL_EXIT_CALC_ELEMENT_READ where the field is calculated.
Add the annotations to the field in the CDS view (consumption view):
@ObjectModel: { virtualElement : true<(>,<)>
virtualElementCalculatedBy: 'ABAP:CL_xxx_EXIT'
}
cast( 0 as MYAMOUNT ) as GrossAmount<(>,<)>

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.

SADL_GW_DT_CDS002 - Details

• The SAP error message SADL_GW_DT_CDS002 indicates that a calculated field is not allowed in the context of the operation you are trying to perform. This error typically arises when working with Core Data Services (CDS) views in SAP, particularly when using the SAP Gateway or when trying to expose CDS views as OData services.
  
  Cause:
  
  Calculated Fields: The error occurs because the CDS view contains a calculated field that is not supported in the context of the operation. This can happen if the calculated field is not defined correctly or if it is not allowed to be used in the specific scenario (e.g., in an OData service).
  OData Service Limitations: Certain calculated fields may not be compatible with the OData service due to the way they are defined or the data types involved.
  Data Model Constraints: The underlying data model may impose restrictions on the use of calculated fields, especially if they are not