Сохранение в формате xml

echo '<?xml version="1.0" encoding="UTF-8"?>
<yml_catalog date="' . date('Y-m-d H:i') . '">
<shop>
<name></name>
<company></company>
<url></url>
 
<currencies>
<currency id="RUR" rate="1"/>
<currency id="USD" rate="2"/>
<currency id="EUR" rate="3"/>
</currencies>
 
<categories>
';
    
    $result = pg_query($dbconnect, $getCategoty);
    while ($row = pg_fetch_row($result)) {
echo '<category id="' . $row['0'] . '">' . $row['1'] . '</category>
';
    }
    pg_close($dbconnect);
 
echo'</categories>

<?php
header('Content-Type: application/xml');
echo '<?xml version="1.0" encoding="UTF-8"?>';
// ...

$h = fopen("my_file.xml","x");
fwrite($h, '<yml_catalog date="2018-02-26 03:28">
<shop>
<name></name>
<company></company>
<url></url>
 
<currencies>
<currency id="RUR" rate="1"/>
<currency id="USD" rate="2"/>
<currency id="EUR" rate="3"/>
</currencies>
 
<categories>
<category id="20">Сопутствующее</category>
<category id="17">Аксессуары</category>
<category id="24">Готовое решение</category>
<category id="5">Ванны</category>
<category id="6">Унитазы / биде</category>
<category id="16">Душ</category>
<category id="23">Инсталляции</category>
<category id="8">Смесители</category>
<category id="7">Полотенцесушители</category>
<category id="1">Напольная</category>
<category id="2">Настенная</category>
<category id="21">Мозаика</category>
<category id="26">Трапы, душевые лотки</category>
<category id="4">Раковины</category>
<category id="19">Декор</category>
<category id="28">Тумба с раковиной</category>
<category id="29">Шкаф-зеркало</category>
<category id="30">Зеркало</category>
<category id="31">Шкаф</category>
<category id="32">Шкаф-пенал</category>
<category id="33">Тумба</category>
<category id="34">Столик</category>
<category id="35">Полка</category>
<category id="36">Консоль</category>
<category id="37">Банкетка</category>
</categories>');
fclose($h);