多个for循环 - 如何打印数据

i want to make a website something like popurls.com, but I will use static data stored in MySQL database. Btw I use php/mysql.
In each list i want to show around 10 links (just like on popurls). In that case, if I would have 20 lists, i would need to make 20 'for' loops (for each particular list).
My question is; is there some better way to print that 20 lists instead of using 20 'for' loops in php.

a for loop or a foreach loop will work fine, but it will be a lot less coding if you just create a single for loop and push content into an array of arrays or an array of strings... you can then do whatever you'd like with the actual content (assuming we're grouping by a column category. I'll use an example that uses an array of strings (and the query that I reference is explained here: http://explainextended.com/2009/03/06/advanced-row-sampling/)

$query = mysql_query([QUERY THAT GETS ALL ITEMS, BUT LIMITS BY EACH CATEGORY]) or die(mysql_error());
$all_items = array();
while($row=mysql_fetch_array($query)){
   if (!isset($all_items[$row['category']])){ //if it isn't created yet, make it an empty string
       $all_items[$row['category']] = "";
   }
   $all_items[$row['category']] .= "<li><a href='".$row['url']."'>".$row['title]."</a></li>"; //concatinate the new item to this list
}

Now we have an array where the block of HTML for each section is stored in an array keyed by the name of the category. To output each block, just:

echo  $all_items['category name'];

PHP's foreach http://php.net/manual/en/control-structures.foreach.php

Depends a lot on your data input but I could imagine something like this:

<?php


$lists = arrray('list1', 'list2', 'list3');

foreach ($lists as $current) {
    $data = fetch_data_from_mysql($current);
    foreach ($data as $link) {
        echo "<a href=\"$data\">Link</a>";
    }
}

function fetch_data_from_mysql($current)
{
   $list_data = array();

   // do whatever is required to fetch the list data for item $current from MySQL
   // and store the data in $list_data

   return $list_data;
}

You just need two foreach loops. Assuming that you take the data from a mysql table (like you wrote), this could be like this:

$list_query = mysql_query("SELECT * FROM lists";)

while( $list = mysql_fetch_array($list_query) )
{
    echo "<h1>{$list['title']}</h1>";

    $query = mysql_query("SELECT * FROM entries WHERE list_id = {$list['id']}");

    while( $entry = mysql_fetch_array($query) )
    {
        echo "- {$entry['name']}<br />";
    }
}

You can get all the information from the database and parse it into an array, something like

array[<news type1>] = array( link1, link2, link3, etc);
array[<news type2>] = array( link1, link2, link3, etc);

and so on

and on the layout you can use

foreach ($newsCategory AS $categoryLinks) {
  foreach ($categoryLinks AS $newsLink) {
       <show the link and / or extra data>
  }
}

Just store your links in two-dimensional array. That way you'll have to make 1 outer loop (iterating over lists) and 1 inner loop iterating over links in a particular list.

$links = array(
  'science' => array('link1', 'link2', ...),
  'sports' => array('link1', 'link2'),
  // ... and so on
);
foreach ($links as $category => $urls) {
  echo "Links in category: $category
";
  foreach ($urls as $url) {
    echo $url . "
";
  }
}