How To Fix SDDL_PARSER_MSG302 - ON condition in to-parent association must contain a key field

SAP Error Message - Details

• Message type: E = Error

• Message class: SDDL_PARSER_MSG - Message Class for DDL Parser

• Message number: 302

• Message text: ON condition in to-parent association must contain a key field

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message SDDL_PARSER_MSG302 - ON condition in to-parent association must contain a key field ?

  The SAP error message SDDL_PARSER_MSG302 indicates that there is an issue with the definition of a "to-parent" association in your data model. Specifically, it states that the condition for this association must include a key field, which is necessary for the association to function correctly.
  Cause:
  The error typically arises in the context of defining associations in the SAP Data Dictionary or when working with Core Data Services (CDS) views. The "to-parent" association is used to link a child entity to its parent entity, and it requires a key field to establish a proper relationship. If the association is defined without a key field, the system cannot determine how to relate the two entities, leading to this error.
  Solution:
  To resolve this error, you need to ensure that the "to-parent" association includes a key field. Here are the steps you can take:
  
  
  Identify the Association: Locate the definition of the "to-parent" association in your data model or CDS view.
  
  
  Add a Key Field: Modify the association definition to include a key field. This typically involves specifying a field from the child entity that corresponds to a key field in the parent entity.
  For example, if you have a child entity ChildEntity and a parent entity ParentEntity, your association might look something like this:
  association to_parent
      to ParentEntity
      on ChildEntity.parent_id = ParentEntity.id
  Ensure that parent_id is a key field in ChildEntity and id is a key field in ParentEntity.
  
  
  Check Data Model: Review the overall data model to ensure that all associations are correctly defined and that key fields are appropriately used.
  
  
  Activate Changes: After making the necessary changes, activate the data model or CDS view to apply the modifications.
  
  
  Test the Association: Once activated, test the association to ensure that it works as expected and that the error no longer occurs.
  
  
  Related Information:
  
  Key Fields: In SAP, key fields are essential for uniquely identifying records in a database table. Ensure that the fields you are using as keys are defined as such in the data dictionary.
  Associations in CDS Views: When working with CDS views, associations are used to define relationships between entities. Understanding how to properly define these associations is crucial for effective data modeling.
  SAP Documentation: Refer to the official SAP documentation for more detailed information on defining associations and working with the data dictionary.
  
  If you continue to experience issues after following these steps, consider consulting with a colleague or reaching out to SAP support for further assistance.