How To Fix DT122 - Structure & is itself used as a subtype

SAP Error Message - Details

• Message type: E = Error

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

• Message number: 122

• Message text: Structure & is itself used as a subtype

What causes this issue?

The structure currently defined is itself used as an include.

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

The resulting cycles cannot be resolved, so such constructions are not
allowed.

System Response

The structure is not activated.

How to fix this error?

No include used may contain the current structure. Resolve the
corresponding cycles.

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 DT122 - Structure & is itself used as a subtype ?

  The SAP error message DT122 indicates that a structure is being used as a subtype, which is not allowed in the context of the operation you are trying to perform. This error typically arises in ABAP programming when you attempt to define a structure in a way that conflicts with the rules of type definitions in SAP.
  Cause:
  
  Structure Definition: You may have defined a structure that is being used as a subtype in a way that is not permissible. In ABAP, a structure cannot be used as a subtype of another structure or data type.
  Inheritance Issues: If you are trying to create a subtype from a structure, it may lead to this error because structures do not support inheritance in the same way that classes do.
  Data Dictionary Issues: There might be issues in the Data Dictionary where the structure is incorrectly defined or referenced.
  
  Solution:
  
  Review Structure Definitions: Check the definition of the structure in the Data Dictionary (SE11). Ensure that it is not being incorrectly defined as a subtype.
  Change Data Type: If you need to create a subtype, consider using a table type or a class instead of a structure, as these can support inheritance and subtyping.
  Refactor Code: If the error arises from ABAP code, refactor the code to avoid using the structure as a subtype. Instead, use a different approach to achieve the desired functionality.
  Check References: Look for any references to the structure in your code or Data Dictionary and ensure they are correctly defined and used.
  
  Related Information:
  
  ABAP Data Types: Familiarize yourself with the different data types in ABAP, including structures, tables, and classes, to understand their limitations and capabilities.
  SAP Documentation: Refer to the official SAP documentation for guidelines on defining structures and data types.
  Community Forums: Check SAP community forums or Stack Overflow for similar issues and solutions shared by other developers.
  
  If you continue to face issues, consider reaching out to your SAP support team or consulting with an experienced ABAP developer for further assistance.