How To Fix DT279 - Field &: Reference & to class w/o interface cannot be used in DB table &

DT279 - Overview

• Message type: E = Error

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

• Message number: 279

• Message text: Field &: Reference & to class w/o interface cannot be used in DB table &

What causes this issue?

In the definition for a database table, you used a reference to a class
or an interface. This is not possible because the databases do not
recognize such references, that is, fields with this type cannot be
created in the database.

System Response

The activation is rejected.

How to fix this error?

In database tables, you can choose between different types. You can
display these using the input help for the data type.

Error message extract from SAP system. Copyright SAP SE.

DT279 - Details

• The SAP error message DT279 indicates that there is an issue with a reference to a class that does not implement an interface in the context of a database table definition. This typically occurs when you are trying to use a reference type in a database table that is not compatible with the requirements of the database layer.
  
  Cause:
  
  Class Definition: The class you are trying to reference in the database table does not implement any interface. In ABAP, only reference types that implement an interface can be used in database tables.
  Data Dictionary: The data dictionary (DDIC) is strict about the types of references that can be used in database tables. If a reference type does not meet the criteria, it will throw this error.
  Inconsistent Data Model: There may be inconsistencies in your data model where a reference type is expected to be used, but the underlying class does not conform to