How To Fix SADL_GW_DT_CDS045 - Foreign key association &1 may use fields of target primary key only.

SAP Error Message - Details

• Message type: E = Error

• Message class: SADL_GW_DT_CDS - Messages CDS Checks

• Message number: 045

• Message text: Foreign key association &1 may use fields of target primary key only.

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message SADL_GW_DT_CDS045 - Foreign key association &1 may use fields of target primary key only. ?

  The SAP error message SADL_GW_DT_CDS045 indicates that there is an issue with the foreign key association in a Core Data Services (CDS) view. Specifically, it means that the foreign key association is trying to use fields that are not part of the primary key of the target entity. This is a common issue when defining associations in CDS views.
  Cause:
  The error occurs when:
  
  You are trying to create a foreign key association in a CDS view that references fields in the target entity that are not part of its primary key.
  The association definition is incorrect, meaning that the fields used in the association do not match the primary key fields of the target entity.
  
  Solution:
  To resolve this error, you can follow these steps:
  
  
  Check the Target Entity: 
  
  Verify the primary key fields of the target entity (the entity you are trying to associate with). Ensure that you are using only those fields in your association.
  
  
  
  Modify the Association:
  
  Update the association in your CDS view to use only the fields that are part of the primary key of the target entity. 
  For example, if your target entity has a primary key consisting of fields ID1 and ID2, your association should only reference these fields.
  
  
  
  Example of Correct Association:
  define view ZMy_CDS_View
  as select from ZMy_Source
  association [0..1] to ZMy_Target as _Target
  on $projection.Field1 = _Target.ID1 and $projection.Field2 = _Target.ID2
  {
      key Field1,
      key Field2,
      ...
      _Target
  }
  
  
  Check for Composite Keys:
  
  If the target entity has a composite key, ensure that all parts of the composite key are included in the association.
  
  
  
  Activate the CDS View:
  
  After making the necessary changes, activate the CDS view to see if the error is resolved.
  
  
  
  Related Information:
  
  CDS Views: Core Data Services (CDS) are a way to define semantic data models in SAP. They allow for the definition of complex data models and associations.
  Foreign Key Associations: In CDS, foreign key associations are used to link entities based on their keys, allowing for more complex queries and data retrieval.
  SAP Documentation: For more detailed information, refer to the official SAP documentation on CDS views and associations, which provides guidelines and best practices.
  
  By following these steps, you should be able to resolve the SADL_GW_DT_CDS045 error and correctly define your foreign key associations in your CDS views.