# Handle database errors

Use SQLSTATE and request outcomes to distinguish retryable conflicts, invalid input and failed transactions.

Source: https://particledb.ai/reference/errors/

## Common SQLSTATE classes

| Code | Meaning | Application response |
|---|---|---|
| `23505` | Duplicate value for a uniqueness constraint | Reconcile identifiers or return an application conflict |
| `40001` | Transaction conflict | Roll back and retry the complete transaction with a bounded policy |
| `25P02` | Transaction is already aborted | Roll back before issuing new work |
| `42601` | SQL syntax error | Correct the statement; repeated retries will not fix it |
| `0A000` | Unsupported feature | Use a supported operation or redesign the integration |
| `53200` | Memory/resource failure | Reduce the work or adjust a reviewed resource budget |
| `57014` | Query cancellation | Check timeout or cancellation policy and reconcile uncertain writes |

Client libraries expose errors differently. Inspect their structured error fields rather than parsing display text when possible.

## Uncertain writes

A disconnected client may not know whether a commit completed. Use stable request identifiers and read the recorded state before retrying a non-idempotent operation.

## Diagnostics

Record the server version, client version, operation and error code. Remove credentials and private values from shared reports.

[Transactions](/sql/transactions/) · [Troubleshooting](/guides/troubleshooting/)