How To Fix E2181 - Foreign key definition is only possible for fields with data element

SAP Error Message - Details

• Message type: E = Error

• Message class: E2 - DE Data Dictionary

• Message number: 181

• Message text: Foreign key definition is only possible for fields with data element

What causes this issue?

Foreign key maintenance is only permitted for fields with data elements.
- The direct allocation of a data type with length is not sufficient.
- You cannot define a foreign key relationship to a field with a
reference to a data element
- You cannot define a foreign key relationship to a field with a
structure or table type component

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?

If you need a foreign key definition for this field, assign a data
element to this field or ensure that the checkbox 'Reference Type' is
not checked.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message E2181 - Foreign key definition is only possible for fields with data element ?

  The SAP error message E2181, which states "Foreign key definition is only possible for fields with data element," typically occurs when you are trying to create a foreign key relationship in the Data Dictionary (SE11) for a field that does not have a data element associated with it. Foreign keys in SAP are used to enforce referential integrity between tables, and they can only be defined for fields that are linked to data elements.
  Cause:
  
  Field Without Data Element: The field you are trying to define as a foreign key does not have an associated data element. In SAP, a data element defines the technical attributes of a field, including its data type, length, and any associated domain.
  Incorrect Table Structure: The table structure may not be set up correctly, or you may be trying to create a foreign key on a field that is not intended to be a key field.
  
  Solution:
  
  
  Check Field Definition: Ensure that the field you are trying to use for the foreign key has a data element assigned to it. You can do this by:
  
  Going to transaction SE11 (Data Dictionary).
  Entering the table name and checking the field definitions.
  If the field does not have a data element, you will need to create one or modify the field to use an existing data element.
  
  
  
  Create or Assign Data Element:
  
  If the field does not have a data element, you can create a new data element in SE11 and then assign it to the field.
  If there is an existing data element that is appropriate for your field, you can assign it to the field.
  
  
  
  Re-attempt Foreign Key Definition: Once the field has a data element associated with it, you can re-attempt to define the foreign key relationship.
  
  
  Related Information:
  
  Data Elements and Domains: In SAP, a data element is linked to a domain, which defines the technical attributes of the field. Make sure to understand the relationship between data elements and domains when working with table definitions.
  Referential Integrity: Foreign keys are essential for maintaining referential integrity in the database. Ensure that the foreign key you are trying to create points to a valid primary key in the referenced table.
  SAP Documentation: For more detailed information, refer to the SAP Help Portal or the specific documentation related to Data Dictionary and foreign key definitions.
  
  By following these steps, you should be able to resolve the E2181 error and successfully define the foreign key in your SAP system.