使用redis来做计数器完善投票系统

$start = 0;

while (true) {

    // 每次循环取50个用户id

    $users = $DB->query("SELECT uid,votes FROM users LIMIT $start, 50");

    if (!$users) {

        exit();

    }

    $keys = [];

    foreach ($users as $userinfo) {

        $keys[] = "uid:{$userinfo['uid']}:vote";

    }

    $votes = $redis->mget($keys);

    foreach ($votes as $index => $vote) {

        if ($vote != $users[$index]['votes']) {

            $DB->query("UPDATE users SET votes = '$vote' WHERE uid='{$users[$index]['uid']}");

        }

    }

    $start += 50;

}