private Map<String, Object> mapColumns(Product product) {
Map<String, Object> params = new HashMap<>();
params.put("id", product.getId());
params.put("name", product.getName());
params.put("desc", product.getDescription());
params.put("price", product.getPrice());
params.put("seller_id", product.getSeller().getId());
params.put("reg_time", product.getRegisteredTime().format(formatter));
return params;
}
