資料庫讀出來的資料如何與定義好的常量對應

資料庫讀出來的資料怎麼與定義好的常量對應？
consstant.php:
define("town_9","橫瀝");
define("town_10","橋頭");
define("town_11","謝崗");
define("town_12","東坑");
define("town_13","常平");
define("town_14","寮步");
define("town_15","大朗");
define("town_16","黃江");

test.php:
...//資料庫操作
echo $row[0];//$row[0]輸出是town_14
?>

這樣運行test.php顯示出來是town_14,而輸出定義好的常量寮步.這如何是好？
------解決方案--------------------

define("town_9","橫瀝");
define("town_10","橋頭");
define("town_11","謝崗");
define("town_12","東坑");
define("town_13","常平");
define("town_14","寮步");
define("town_15","大朗");
define("town_16","黃江");

//資料庫操作
$row = array();
$row[0] = "town_14";

$defined_constants = get_defined_constants();
echo $defined_constants[$row[0]]; // 寮步

