Error code

SQL Server 2601

SQL SERVER2601
Database Error Code· An error code returned by a database server such as PostgreSQL or MySQL.

What it means

cannot insert duplicate key row in object with unique index — index duplicate violation.

How to fix it

  1. Use MERGE or INSERT with IF NOT EXISTS to handle duplicates before they reach the index.
  2. Delete or update the conflicting existing row.
  3. Review application logic to avoid generating duplicate values for uniquely indexed columns.

Not affiliated with SQL Server. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.