How To Fix SDDL_PARSER_MSG057 - To many associations (cardinality [n..*]) are not allowed here

SAP Error Message - Details

• Message type: E = Error

• Message class: SDDL_PARSER_MSG - Message Class for DDL Parser

• Message number: 057

• Message text: To many associations (cardinality [n..*]) are not allowed here

What causes this issue?

The use of ?to many? associations (cardinality [n..*]) in path
expressions within CDS views is forbidden at the following positions:
WHERE condition: If path expressions with a results set greater than 1
are used within simple comparison operations, the required behavior is
undefined: Does the comparison need to be met for all values or only for
at least one value?
In this case, path expressions with a results set greater than 1 are
forbidden within WHERE conditions.
View extends: When a path expression with a results set greater than 1
is used, the cardinality of the result is modified and hence the use of
theses expressions is forbidden with view extends.

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

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message SDDL_PARSER_MSG057 - To many associations (cardinality [n..*]) are not allowed here ?

  The SAP error message SDDL_PARSER_MSG057 indicates that there are too many associations defined in a particular context, specifically when the cardinality of the association is set to [n..*], which means that it allows for multiple instances of the associated entity. This error typically arises in the context of defining data models, particularly in the SAP Business Application Studio or when working with SAP's Service Definition Language (SDL).
  Cause:
  The error occurs when:
  
  You have defined an association in your data model that allows for an excessive number of instances (e.g., many-to-many relationships) that are not supported in the current context.
  The system has a limit on the number of associations that can be defined for a particular entity or context, and this limit has been exceeded.
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Review the Associations: Check the associations defined in your data model. Look for any associations that are defined with a cardinality of [n..*] and assess whether they are necessary.
  
  
  Limit Cardinality: If possible, change the cardinality of the association to a more restrictive one, such as [0..1] or [1..*], depending on your business requirements. This will reduce the number of instances allowed and may resolve the error.
  
  
  Refactor the Model: If you have multiple associations that are causing the issue, consider refactoring your data model. This may involve:
  
  Merging some entities.
  Creating intermediary entities to handle many-to-many relationships.
  Simplifying the relationships to fit within the allowed limits.
  
  
  
  Check Documentation: Refer to the SAP documentation for guidelines on cardinality and associations. There may be specific limitations or best practices outlined that can help you design your model correctly.
  
  
  Testing: After making changes, test your data model to ensure that it functions as expected and that the error no longer occurs.
  
  
  Related Information:
  
  SAP Documentation: Always refer to the latest SAP documentation for the specific version you are using, as there may be updates or changes in how associations and cardinalities are handled.
  Community Forums: Check SAP Community forums or other developer communities for similar issues and solutions shared by other users.
  SAP Notes: Look for any relevant SAP Notes that might address this specific error or provide additional context on limitations regarding associations.
  
  By following these steps, you should be able to identify the cause of the error and implement a solution to resolve it.