html输出格式化php

I am trying to format some html output from my db using php and here's my problem:

How it should be formated:

...
<li>
    <div class="row-wrapper">
       <div class="some-class-1">ARRAY-ELEMENT-1</div>
       <div class="some-class-1">ARRAY-ELEMENT-2</div>
       <div class="some-class-1">ARRAY-ELEMENT-3</div>
       <div class="some-class-2">ARRAY-ELEMENT-4</div>
    </div>
    <div class="row-wrapper">
      <div class="some-class-1">ARRAY-ELEMENT-5</div>
      <div class="some-class-1">ARRAY-ELEMENT-6</div>
      <div class="some-class-1">ARRAY-ELEMENT-7</div>
      <div class="some-class-2">ARRAY-ELEMENT-8</div>
    </div>
    <div class="row-wrapper">
      <div class="some-class-1">ARRAY-ELEMENT-9</div>
      <div class="some-class-1">ARRAY-ELEMENT-10</div>
      <div class="some-class-1">ARRAY-ELEMENT-11</div>
      <div class="some-class-2">ARRAY-ELEMENT-12</div>
    </div>
</li>
<li>
  <div class="row-wrapper">
    <div class="some-class-1">ARRAY-ELEMENT-13</div>
    <div class="some-class-1">ARRAY-ELEMENT-14</div>
    <div class="some-class-1">ARRAY-ELEMENT-15</div>
    <div class="some-class-2">ARRAY-ELEMENT-16</div>
  </div>
  <div class="row-wrapper">
    <div class="some-class-1">ARRAY-ELEMENT-17</div>
    <div class="some-class-1">ARRAY-ELEMENT-18</div>
    <div class="some-class-1">ARRAY-ELEMENT-19</div>
    <div class="some-class-2">ARRAY-ELEMENT-20</div>
  </div>
  <div class="row-wrapper">
    <div class="some-class-1">ARRAY-ELEMENT-21</div>
    <div class="some-class-1">ARRAY-ELEMENT-22</div>
    <div class="some-class-1">ARRAY-ELEMENT-23</div>
    <div class="some-class-2">ARRAY-ELEMENT-24</div>
  </div>
</li>
... etc.

Data is held inside an array gathered from mysql db, so far I got to this:

$num_thumbs = 4; //Number od elemets in a row
$result = myQueryFunction("SELECT * FROM table_name ORDER BY Id ASC"); 
$num_rows = mysql_num_rows($result); 
if (!empty($num_rows)) {
  while ($row = mysql_fetch_array($result)) {
    $thumbs_array[] = "<a href=\"" . $row[0] . "\"><img src=\"" . $row[1] . "\"";
  }
  $thumb_p = "<div>
";
  mysql_free_result($result);
  $i = 1;
  foreach ($thumbs_array as &$thumb_link) {
    if ($i == $num_thumbs) {
        $i = 1;
        $thumb_p .= "<div class=\"some-class-2\">" . $thumb_link . "</div>";
        $thumb_p .= "</div>
<div class=\"row-wrapper\">
";
    } else {
            $thumb_p .= "\t
<div class=\"some-class-1\">" . $thumb_link . "</div>";
        $i++;
    }

  }
  $thumb_p .= "
</div>
";
}

print($thumb_p);

this covers only this part of code formatting:

  <div class="row-wrapper">
    <div class="some-class-1">ARRAY-ELEMENT-13</div>
    <div class="some-class-1">ARRAY-ELEMENT-14</div>
    <div class="some-class-1">ARRAY-ELEMENT-15</div>
    <div class="some-class-2">ARRAY-ELEMENT-16</div>
  </div>
  <div class="row-wrapper">
    <div class="some-class-1">ARRAY-ELEMENT-17</div>
    <div class="some-class-1">ARRAY-ELEMENT-18</div>
    <div class="some-class-1">ARRAY-ELEMENT-19</div>
    <div class="some-class-2">ARRAY-ELEMENT-20</div>
  </div>
  <div class="row-wrapper">
    <div class="some-class-1">ARRAY-ELEMENT-21</div>
    <div class="some-class-1">ARRAY-ELEMENT-22</div>
    <div class="some-class-1">ARRAY-ELEMENT-23</div>
    <div class="some-class-2">ARRAY-ELEMENT-24</div>
  </div>

I've been thinking of using some variable $newList = null; that will be updated at each row, so I can check if it has changed the next one. any ideas? Thanks in advance :)

It seems you're trying to put an li every three div. In this case, you can do this :

$thumb_p = "<li>
<div class=\"row-wrapper\">
";
mysql_free_result($result);
$i = 1;
$j = 0;
foreach ($thumbs_array as &$thumb_link) {
  if ($i == $num_thumbs) {
      $i = 1;
      $thumb_p .= "<div class=\"some-class-2\">" . $thumb_link . "</div>";
      $thumb_p .= "</div>
";
      if($j == 3)
      {
          $thumb_p .= "</li>
<li>";
          $j = 0;
      }
      $thumb_p .= "<div class=\"row-wrapper\">
";
      $j++;
  } else {
      $thumb_p .= "\t
<div class=\"some-class-1\">" . $thumb_link . "</div>";
      $i++;
  }
}
$thumb_p .= "
</div>
</li>
";

I can't actually try it but I think it's okay. A li is added every three row-wrapper you print.