php代码优化问题 双层foreach如何优化

foreach ($rows as $key1 => $row) {
foreach ($country as $key2 => $val) {
if ($row['country'] == $val['id']) {
$rows[$key1]['country_as'] = $country[$key2]['country_ch'];
}
}
}

foreach ($rows as $key1 => $row) {
foreach ($country as $key2 => $val) {
if ($row['country'] == $val['id']) {
$rows[$key1]['country_as'] = $country[$key2]['country_ch'];
}
}
}

http://blog.csdn.net/jayxujia123/article/details/5990168

$country = array_column($country,null,'id');

foreach($rows as $k=>$v){

            if(isset($country[$v['country']])){

                $rows[$k]['country_as']=$country[$v['country']]['country_ch'];

            }

}

这样？
我也是问了大佬才知道的 借用大佬的代码