php mysql实现标签云的实例代码

php与mysql结合实现的标签云效果，完整代码，如下：

<?php
/**
* php与mysql实现的标签云效果
* by www.jb200.com
*/
$db_host = "localhost";
$db_user = "db_user";
$db_pass = "pass";
$db_name = "db_name";

mysql_connect($db_host, $db_user, $db_pass) or die(mysql_error());
mysql_select_db($db_name);

function tag_info() { 
  $result = mysql_query("SELECT * FROM tags GROUP BY tag ORDER BY count DESC"); 
  while($row = mysql_fetch_array($result)) { 
    $arr[$row['tag']] = $row['count'];
  } 
  ksort($arr); 
  return $arr; 
}

function tag_cloud() {

    $min_size = 10;
    $max_size = 30;

    $tags = tag_info();

    $minimum_count = min(array_values($tags));
    $maximum_count = max(array_values($tags));
    $spread = $maximum_count - $minimum_count;

    if($spread == 0) {
        $spread = 1;
    }

    $cloud_html = '';
    $cloud_tags = array(); // create an array to hold tag code
    foreach ($tags as $tag => $count) {
        $size = $min_size + ($count - $minimum_count) 
            * ($max_size - $min_size) / $spread;
        $cloud_tags[] = '<a style="font-size: '. floor($size) . 'px' 
            . '" class="tag_cloud" target="_blank" href="http://www.jb200.com/index.php?s=' . $tag 
            . '" title="'' . $tag  . '' returned a count of ' . $count . '">' 
            . htmlspecialchars(stripslashes($tag)) . '</a>';
    }
    $cloud_html = join("n", $cloud_tags) . "n";
    return $cloud_html;
}
?>

2，css样式表
 

3，显示标签云的区域