Tag Clouds 的一个PHP+MySql 实现

Tag Clouds 的一个很不错的实现，简单易用，代码来自这里，可以参考这里。

 <?php

// connect to database at some point

// In the SQL below, change these three things:
// thing is the column name that you are making a tag cloud for 
// id is the primary key
// my_table is the name of the database table

$query = "SELECT thing AS tag, COUNT(id) AS quantity 
  FROM my_table
  GROUP BY thing
  ORDER BY thing ASC";

$result = mysql_query($query);

// here we loop through the results and put them into a simple array:
 // $tag['thing1'] = 12;
// $tag['thing2'] = 25;
// etc. so we can use all the nifty array functions
// to calculate the font-size of each tag 
while ($row = mysql_fetch_array($result)) {

    $tags[$row['tag']] = $row['quantity'];
}

// change these font sizes if you will
$max_size = 250;  // max font size in %
$min_size = 100; // min font size in %

// get the largest and smallest array values
$max_qty = max(array_values($tags)); 
$min_qty = min(array_values($tags));

// find the range of values
$spread = $max_qty - $min_qty;
if (0 == $spread) { // we don't want to divide by zero 
    $spread = 1;
}

// determine the font-size increment
// this is the increase per tag quantity (times used)
$step = ($max_size - $min_size)/($spread); 

// loop through our tag array
foreach ($tags as $key => $value) {

    // calculate CSS font-size
    // find the $value in excess of $min_qty 
    // multiply by the font-size increment ($size)
    // and add the $min_size set above
    $size = $min_size + (($value - $min_qty) * $step);
     // uncomment if you want sizes in whole %:
    // $size = ceil($size);

    // you'll need to put the link destination in place of the  #
    // (assuming your tag links to some sort of details page)
    echo '<a href="#" style="font-size: '.$size.'%"';
     // perhaps adjust this title attribute for the things that are tagged
    echo ' title="'.$value.' things tagged with '.$key.'"';
    echo '>'.$key.'</a> '; 
    // notice the space at the end of the link
}

?>