How To Fix DO855 - Explicit key definition is not allowed (row type unstructured)

SAP Error Message - Details

• Message type: E = Error

• Message class: DO - Dictionary: Mass activation of domains and data elements

• Message number: 855

• Message text: Explicit key definition is not allowed (row type unstructured)

What causes this issue?

You can only explicitly assign a key to a table type if the row type of
the table type is a structure.

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

Choose a structured <DS:TX.DDDOC_ROWTYPE>row type</> or a more suitable
<DS:TX.DDDOC_KEYDEF>key definition</> for the specified row type.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message DO855 - Explicit key definition is not allowed (row type unstructured) ?

  The SAP error message DO855, which states "Explicit key definition is not allowed (row type unstructured)," typically occurs in the context of data definitions in ABAP Dictionary or when working with internal tables in ABAP programs. This error indicates that you are trying to define a key for a row type that is considered unstructured, which is not permitted.
  Cause:
  
  Unstructured Row Type: The error arises when you attempt to define a key for a row type that does not have a structured format. In ABAP, a structured row type is one that has a defined structure with fields, while an unstructured row type does not have a fixed set of fields.
  Internal Table Definition: If you are defining an internal table and trying to specify a key for it, but the row type is declared as unstructured (e.g., using TYPE ANY or similar), this will trigger the error.
  
  Solution:
  To resolve the DO855 error, you need to ensure that the row type you are working with is structured and has a defined key. Here are the steps you can take:
  
  
  Define a Structured Row Type:
  
  Ensure that the row type you are using is defined with a specific structure. For example, you can define a structure using TYPES:
  TYPES: BEGIN OF ty_my_structure,
           field1 TYPE string,
           field2 TYPE i,
         END OF ty_my_structure.
  
  Then, declare your internal table using this structured type:
  DATA: it_my_table TYPE TABLE OF ty_my_structure.
  
  
  
  
  Specify a Key:
  
  If you need to define a key for your internal table, make sure that the fields you are using as keys are part of the structured row type. You can define a key using the WITH KEY addition:
  DATA: it_my_table TYPE SORTED TABLE OF ty_my_structure WITH UNIQUE KEY field1.
  
  
  
  
  Review Your Code:
  
  Go through your code to ensure that you are not inadvertently using unstructured types where a structured type is required. Check for any declarations that might be causing the issue.
  
  
  
  Related Information:
  
  ABAP Dictionary: Understanding how to define structures and tables in the ABAP Dictionary is crucial for avoiding this error.
  Internal Tables: Familiarize yourself with the different types of internal tables in ABAP (standard, sorted, hashed) and their key definitions.
  SAP Documentation: Refer to the official SAP documentation for more details on data types, structures, and internal tables in ABAP.
  
  By ensuring that you are using structured types and correctly defining keys, you should be able to resolve the DO855 error in your SAP environment.