How To Fix RSRTS_CDS170 - Alias &1: nested functions (for example, conversion) are not supported

SAP Error Message - Details

• Message type: E = Error

• Message class: RSRTS_CDS - Messages Transient CDS Queries

• Message number: 170

• Message text: Alias &1: nested functions (for example, conversion) are not supported

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message RSRTS_CDS170 - Alias &1: nested functions (for example, conversion) are not supported ?

  The SAP error message RSRTS_CDS170 indicates that there is an issue with the use of nested functions in a Core Data Services (CDS) view or query. Specifically, it suggests that the query is attempting to use a function (like a conversion function) within another function, which is not supported in the context of the query being executed.
  Cause:
  The error typically arises when:
  
  You are trying to use a function that is not allowed to be nested within another function in the CDS view or query.
  The query may involve complex calculations or transformations that exceed the capabilities of the underlying database or the CDS framework.
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Review the Query: Check the CDS view or query definition for any nested functions. Look for instances where one function is being called within another (e.g., using a conversion function inside an aggregation function).
  
  
  Refactor the Query: If you find nested functions, try to refactor the query to avoid nesting. For example, you can:
  
  Break down the query into simpler parts.
  Create intermediate calculations or views that perform the necessary transformations separately before combining them in the final query.
  
  
  
  Use Calculated Fields: If applicable, consider using calculated fields in the CDS view to perform transformations separately rather than nesting them.
  
  
  Check Documentation: Refer to the SAP documentation for the specific functions you are using to ensure they are compatible and supported in the context you are applying them.
  
  
  Test Incrementally: After making changes, test the query incrementally to ensure that each part works as expected before combining them.
  
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that might address this specific error or provide additional guidance on using functions in CDS views.
  SAP Community: Engage with the SAP Community forums to see if others have encountered similar issues and what solutions they have found.
  Performance Considerations: Be mindful of performance implications when refactoring queries, as overly complex queries can lead to performance degradation.
  
  By following these steps, you should be able to resolve the RSRTS_CDS170 error and successfully execute your CDS view or query.