这些选项中哪个更优化?
在 MySQL 中内爆
$rsFriends = $cnn->Execute('SELECT CAST(GROUP_CONCAT(id_friend) AS CHAR) AS friends
FROM table_friend
WHERE id_user = '.q($_SESSION['id_user']));
$friends = $rsFriends->fields['friends'];
echo $friends;
对比
PHP内爆
$rsFriends = $cnn->Execute('SELECT id_friend
FROM table_friend
WHERE id_user = '.q($_SESSION['id_user']));
while(!$rsFriends->EOF) {
$friends[] = $rsFriends->fields['id_friend'];
$rsFriends->MoveNext();
}
echo implode(',',$friends);