如何在while循环中将项目分组？

Question

I am trying to group my output from my while loop, in PHP.

What I am trying to achieve, is I want each "box" with the same ' exposure ' to be grouped together, then whenever a new box, with a new ' exposure ' comes, a line break should appear, and the next group of exposure should be grouped.

Currently, I have this PHP code:

//Select from advertisements.   
global $dbh;
$r = $dbh->prepare("
SELECT * FROM advertisements 
WHERE exposure!='0' 
AND `status`='2' 
AND (clicks_left_micro>0 
OR clicks_left_mini>0 
OR clicks_left_standard>0 
OR clicks_left_extended>0 
OR fixed='1') 

ORDER BY exposure DESC, fixed DESC");
$r->execute();

$last = null;
while($row=$r->fetch(PDO::FETCH_ASSOC)){

    $exposure = $row['exposure'];
    switch ($exposure) {
        case 1:
            $type = "";
            break;
        case 2:
            $type = "ads-orange";
            break;
        case 3:
            $type = "ads-green";
            break;
        case 4:
            $type = "ads-blue";
            break;
    }

    if ($row['token'] != $last) {
        echo '

            <a href="#">
                <div class="col-xs-4 ads-box '.$type.'">
                    <div class="title">'.$row['title'].'</div>
                    <div class="content">'.$row['description'].'</div>
                </div>      
             </a>
        ';
        $last = $row['token'];
    }

}

The above code, will just print them out like this:

https://docs.google.com/file/d/0Bw9EQNU6ms6jUXVyY1pndVlpY2c/edit?usp=drivesdk

Although, what I want is like this:

https://docs.google.com/file/d/0Bw9EQNU6ms6jU0JYaDlHWEZsN1k/edit?usp=drivesdk

How can I achieve this?

Answer 1

I would make an array with all the 'exposures'.

$dataArray = array();
foreach ($result as $value){
    $dataArray[$value['exposure']][] = $value;
}

This will result in an array ($dataArray) with all your exposure catagories in their respective index.

Now you can loop through each of your 'exposures':

foreach ($dataArray as $exposure => $value){

    echo 'Exposure: '.$exposure.'<br/>';
    foreach ($value as $item){
        // Any item information here.
    }
    echo '<hr>';
}