How To Fix DMC_EXCEPTION004 - Only source structures can be defined as lookup tables

SAP Error Message - Details

• Message type: E = Error

• Message class: DMC_EXCEPTION - Message class for exception texts

• Message number: 004

• Message text: Only source structures can be defined as lookup tables

A lookup table contains records that are looked up from a field in
another table to fill in the value of that field. The table can be
referenced by rules and used by mapping operations, but does not
directly provide content for fields in the target system.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message DMC_EXCEPTION004 - Only source structures can be defined as lookup tables ?

  The SAP error message DMC_EXCEPTION004: Only source structures can be defined as lookup tables typically occurs in the context of SAP Data Management and Data Integration processes, particularly when working with Data Migration Cockpit (DMC) or similar tools.
  Cause:
  This error indicates that you are trying to define a lookup table using a structure that is not a source structure. In SAP, lookup tables are used to map values from one set of data to another, and they must be based on source structures that are defined in the data model. If you attempt to use a target structure or any other non-source structure as a lookup table, this error will be triggered.
  Solution:
  To resolve this error, you should ensure that:
  
  
  Use Source Structures: Verify that the structure you are trying to define as a lookup table is indeed a source structure. You can check the data model or the configuration settings to confirm this.
  
  
  Define Lookup Tables Correctly: If you need to create a lookup table, make sure to select a valid source structure that is appropriate for your data mapping needs.
  
  
  Review Data Model: If you are unsure about the structures available, review the data model in your DMC or relevant SAP tool to identify which structures are classified as source structures.
  
  
  Consult Documentation: Refer to the official SAP documentation or help resources for guidance on how to properly define lookup tables and the requirements for source structures.
  
  
  Check for Updates: Ensure that your SAP system is up to date, as there may be patches or updates that address related issues or improve functionality.
  
  
  Related Information:
  
  SAP Data Migration Cockpit (DMC): This tool is used for migrating data into SAP systems. Understanding its architecture and how it handles data structures is crucial for effective data migration.
  Data Mapping: Familiarize yourself with the concepts of data mapping and transformation in SAP, as this will help you understand how lookup tables fit into the overall data migration process.
  SAP Community and Forums: If you continue to face issues, consider reaching out to the SAP Community or forums where other users and experts can provide insights and solutions based on their experiences.
  
  By following these steps, you should be able to resolve the DMC_EXCEPTION004 error and successfully define your lookup tables in SAP.