这个循环有更好的解决方案吗？

Question

I'm making a website which basically displays a random image but I need a better bit of code of what I have at the moment. I'm hoping someone could come up with a better solution.

$p = $_GET["p"];
$qrynumrows = mysql_query("SELECT * FROM pictures");
$numrows = mysql_num_rows($qrynumrows);

if (!isset($p)) {
    $randid = rand(1, $numrows);
    $qryrecord = mysql_query("SELECT * FROM pictures WHERE id='$randid'");

    while ($row = mysql_fetch_array($qryrecord)) {
        $rowp = $row["p"];
        $rowremove = $row["remove"];
    }

    if ($rowremove == 1) {
        header("Location: http://www.lulzorg.com/");
        exit();
    }
    else {
        header("Location: http://www.lulzorg.com/?p=$rowp");
        exit();
    }       
}

So what it's doing is picking a random record from the database but it needs to check whether the record is allowed. The bit of code works fine but I'm sure there's a better/faster way to do it.

If $rowremove is equal to 0 then the image is allowed to display. If $rowremove is equal to 1 then the image is NOT allowed to display.

Thanks.

Answer 1

Instead of generating a random ID, just select the first row after ordering the results by RAND(). In addition, check for NOT remove (equivalent to remove = 0) in the rows to remove the need to check the rows individually.

$p = $_GET["p"];

if (is_int($p))
{
    $qryrecord = mysql_fetch_row(mysql_query("SELECT p FROM pictures WHERE NOT remove ORDER BY RAND() LIMIT 1"));
    $rowp = $qryrecord[0];
    header("Location: http://www.lulzorg.com/?p=$rowp");
    exit();
}