connect_error) { http_response_code(500); die(json_encode(['error' => 'DB is down: Connection failed.', 'details' => $conn->connect_error])); } // Run test query $result = $conn->query('SELECT 1'); if (!$result) { http_response_code(500); die(json_encode(['error' => 'DB is down: Query failed.', 'details' => $conn->error])); } echo json_encode(['message' => 'DB is online']); $conn->close();