Function classifyErrorCode

server/conn_errors.go:69–118

classifyErrorCode returns the most appropriate PostgreSQL SQLSTATE for a DuckDB error. Transaction conflicts get 40001 (serialization_failure), which signals PG-aware clients to retry. Query cancellations get 57014. Remaining errors are classified by DuckDB's exception-type prefix; the prefix is the

(err error)

// errors are classified by DuckDB's exception-type prefix; the prefix is the
// only signal the Go driver exposes today, so we parse the message string.
func classifyErrorCode(err error) string {
	// Wire-side SQLSTATE: 57014 is correct for any cancellation regardless of
	// whether the caller drove it. Use isQueryCancelled here, not the
	// clientConn-aware variant — classifyErrorCode is called from contexts
	// that don't have a *clientConn (e.g., direct test fixtures).
	if isQueryCancelled(err) {
		return "57014"
	}
	if isDuckLakeTransactionConflict(err) {
		return "40001" // serialization_failure — client should retry
	}

	// Workers reach the control plane over Arrow Flight SQL, so DuckDB errors
	// arrive wrapped as "flight execute update: rpc error: code = X desc = <msg>".
	// Unwrap to recover the underlying DuckDB exception message so the prefix
	// classifiers below apply; otherwise every DuckLake worker error
	// would fall through to XX000 and the client would see the raw rpc string.
	msg := unwrapFlightError(err.Error())
	switch {
	case strings.HasPrefix(msg, "Catalog Error:"):
		return catalogErrorCode(msg)
	case strings.HasPrefix(msg, "Binder Error:"):
		return binderErrorCode(msg)
	case strings.HasPrefix(msg, "Parser Error:"):
		return "42601" // syntax_error
	case strings.HasPrefix(msg, "Conversion Error:"):
		return conversionErrorCode(msg)
	case strings.HasPrefix(msg, "Out of Range Error:"):
		return "22003" // numeric_value_out_of_range
	case strings.HasPrefix(msg, "Constraint Error:"):
		return constraintErrorCode(msg)
	case strings.HasPrefix(msg, "Permission Error:"):
		return "42501" // insufficient_privilege
	case strings.HasPrefix(msg, "Not implemented Error:"),
		strings.HasPrefix(msg, "Invalid Input Error: Not implemented"):
		return "0A000" // feature_not_supported
	case strings.HasPrefix(msg, "Transaction Error:"),
		strings.HasPrefix(msg, "TransactionContext Error:"):
		return "25000" // invalid_transaction_state — DuckDB emits both prefixes
	case strings.HasPrefix(msg, "Dependency Error:"):
		return "2BP01" // dependent_objects_still_exist
	}
	// Unknown error class — no DuckDB prefix matched. These are
	// typically infra issues (gRPC failures, IO errors, internal panics)
	// rather than user input issues. Classify as XX000 (internal_error)
	// so isUserQueryError correctly routes them to the system-error log
	// path. If a future DuckDB error needs to land in a user class, add
	// a prefix branch above instead of moving the fallback.
	return "XX000"
}

// transformErrorSQLState returns the SQLSTATE for a transpiler-detected error.
// A transform may attach an explicit code (e.g. 0A000 for an unsupported