Cannot insert: duplicate value violates unique constraint

Attempting to insert a record with a duplicate value in a field marked as unique in the dictionary, such as sys_id, number field, or custom unique fields. (high likelihood)

Data import or migration scripts creating records without checking for existing values in unique constraint fields like external keys or slug fields. (high likelihood)

Concurrent script execution creating multiple records simultaneously with the same unique field values, causing race conditions. (medium likelihood)

Business Rules or workflows automatically generating values for unique fields that conflict with existing records due to insufficient uniqueness logic. (medium likelihood)

Manual record creation through forms or REST API calls that bypass client-side validation for unique field constraints. (low likelihood)

Step 1: Check the System Log at System Diagnostics > Log > Application Log to identify the exact table and field causing the unique constraint violation.

Step 2: Navigate to System Definition > Dictionary and search for the problematic field to confirm its unique constraint settings and identify the table involved.

Step 3: Query the target table to find existing records with the duplicate value using a GlideRecord query or list view filter to understand the conflict.

Step 4: Modify your script to check for existing records before insertion using gr.get() or addQuery() methods to validate uniqueness before calling insert().

Step 5: Implement proper error handling in your script using try-catch blocks around GlideRecord operations to gracefully handle constraint violations.

Step 6: If the duplicate record should be updated instead of inserted, modify your logic to use insertOrUpdate() method or conditional update operations.

Step 7: For data imports, implement pre-validation scripts that check for existing unique values and either skip duplicates or generate alternative unique values.

Step 8: Test your modified script in a development instance to ensure it handles both new records and potential duplicates correctly without throwing constraint violations.