3713221 - CAP POST : 409006 "Unique constraint violated when inserting or updating entity"

• POST (create entity) CAP Service hitting error like:
  
  

  HTTP/1.1 409 
  OData-Version: 4.01
  X-Content-Type-Options: nosniff
  X-XSS-Protection: 0
  Cache-Control: no-cache, no-store, max-age=0, must-revalidate
  Pragma: no-cache
  Expires: 0
  Content-Type: application/json
  Content-Length: 124
  Date: Sun, 08 Feb 2026 07:51:12 GMT
  Connection: close

  {
    "error": {
      "code": "409006",
      "message": "Unique constraint violated when inserting or updating entity 'AdminService.Products'"
    }
  }

• CDS log shows:
  
  2026-02-08T07:51:12.684Z  INFO 132110 --- [io-8080-exec-10] c.s.c.a.o.v4.processors.CdsProcessor     : Exception marked the ChangeSet 13 as cancelled: Unique constraint violated when inserting or updating entity 'AdminService.Products' (service 'PersistenceService$Default', event 'CREATE', entity 'AdminService.Products')

• CAP Java
• HANA Cloud

HTTP/1.1 409, 409, c.s.c.a.o.v4.processors.CdsProcessor, Unique constraint violated when inserting or updating entity, 409006  , KBA , BC-XS-CDX-JAV , SAP CAP – Java runtime , Problem