How is it ? For eg Like

function one_function ($var){
           one_function(332);
}

OK , So , how to related with this post title ? I would like to say absolutely related with recursion. Let’s say, we would like to create category with parent and child.so, we have one table in database, category table. Table Structure Like:

So, now I have created one table. I would like to get the out put like:

Main Parrent
- Sub Parent
– Child of sub parent
Parent 2
- Child 2
– Child of child 2
- Child 3

So, how will you do it? How could we get it?

If you write the codes like, for eg :

   $result = mysql_query ();
   while ( $row = mysql_fetch_assoc($result) ){

      echo $row[name];

      $result = mysql_query ();
      while ( $row = mysql_fetch_assoc($result) ){

            echo '- '.$row[name];
      }

   }

It would be work. But. If you have 3 or 4 or 5 levels and so on, you will got the trouble. So, what is the better way for that table? Shell we use recursion ?

I have wrote some code snippets like :

function display_child($parent, $level) {

		$content= array();
		$sql = "SELECT * from test WHERE p_id='$parent'";
		$result = mysql_query($sql);
	   	while ($row = mysql_fetch_array($result)) {
		   	array_push($content,$row['id']);

			if (in_array($parent, $content)){
				echo $row['name']."
";

			}

			echo str_repeat('-',$level)." ".$row['name']."
";
			display_child($row['id'], $level+1);
	   }

}

Usage – display_child( parent_id, level )

     display_children(0,0);

I hope it would be useful for some of your projects. Enjoy !!!!

Download Source ( size 2.7 kB)

Let says, we have user table. Normally, we write SQL query like :

SELECT * FROM user WHERE user_id = 111

OK, If your user_id is added by auto increment, it’s simply write 111 – 1 and 111 + 1 in your program. If not, how could we got it?
Let’s see.

SELECT *,
(SELECT user_id FROM user WHERE user_id < u.user_id ORDER BY user_id DESC LIMIT 1) AS user_prev,
(SELECT user_id FROM user WHERE user_id > u.user_id ORDER BY user_id ASC LIMIT 1) AS user_next
FROM user AS u WHERE u.user_id=111

Enjoy !!! I hope it would be useful for you.

For normal function ..

<?

function calc ( $a, $b)
{

$sum = $a+$b;
return $sum;

}

echo $calc(2,3);

?>

So, If you would like to return two or more value from that function, just only return as an array. Let’s see.

<?php

function calc($a,$b){

$sum = $a+$b;
$multiply = $a * $b;
$divided = $a/$b;
$modulus = $a%$b;

return array( 'sum'=>$sum, 'multiply'=>$multiply, 'divided'=> $divided, 'modulus'=>$modulus );

}

$data = calc(3,4);

echo 'Sum value: '.$data['sum'].'<br />';
echo 'Multiply value: '.$data['multiply'].'<br />';
echo 'Divided value: '.$data['divided'].'<br />';
echo 'Modulus value: '.$data['modulus'].'<br />';

?>

Enjoy !!!

I would like to show you an example to create xml playlist. So you can use this in flash mp3 player like JW Player. I have created songs table in my database. songs_id, album_id, songs_title and songs_link fields are included in this table.

In PHP file :

<?php
 header('Content-type: text/xml');
 $db_host = "localhost" ; // MySQL Host
 $db_user = "root" ;    // Database Username
 $db_password = "" ; // Database Password
 $db_name = "music" ; // Database Name

 $db_link = mysql_connect("$db_host","$db_user","$db_password");
 mysql_select_db($db_name, $db_link);

?>
 <playlist version="1" xmlns="http://xspf.org/ns/0/">
 <trackList>
 <?php
 $album_id = $_GET[aid];
 $songs = "SELECT * From songs WHERE album_id='$album_id' ORDER BY song_title ASC";
 $songs_list = mysql_query( $songs, $db_link );
 $songs_total = mysql_num_rows( $songs_list );
 if( $songs_total == 0 )    {    exit;    }
 for( $f = 0; $f < $songs_total; $f++ )
 {
 $each = mysql_fetch_assoc( $songs_list );
 ?>
 <track>
 <title><?=$each['song_title']?></title>
 <location>http://www.yourdomain.com/<?=$each['song_link']?></location>
 </track>
 <?php

 } // End of loop

 ?>
 </trackList>
 </playlist>

Then you can use call this file with album id like xml.php?aid=10.

Download Source ( size 745 B)

However, this is a lot of lines in the file. If you want to put into a lot of pages, all of code you need to put into those pages. We have to take care about this. That’s while I have changed to class and functions. That’s very easy to use. I will share it back.

Firstly I have created class and function in the paganition.php file.

For usage :

require_once('pagination.php');
 $sql = 'SELECT * FROM contact';
 $page_name = "page.php";

 //  pagination($query, $adjacents, $row_per_page, $page_name)
 $pager = new pagination($sql, 3, 20, $page_name );
 $rs = $pager->paginate();

 while($each = mysql_fetch_assoc($rs))
 {
 // Your Loop Here
 echo $each[name];
 }

 // Pages Navagation
 echo $pager->pages();

So, Page links will be come like “pagename.php?page=” . If you would like to use with .htaccess some think like http://www.yourdomain.com/content/page/page_number , you can easily to change at pagination.php . Find, “?page=” and replace with “/” . Then, you can use at page name like

$page_name = "http://www.yourdomain.com/content/page";

In CSS.

div.pagination {
 padding: 3px;
 margin: 3px;
}

div.pagination a {
 padding: 2px 5px 2px 5px;
 margin: 2px;
 border: 1px solid #AAAADD;

 text-decoration: none; /* no underline */
 color: #000099;
}

div.pagination a:hover, div.pagination a:active {
 border: 1px solid #000099;

 color: #000;
}

div.pagination span.current {
 padding: 2px 5px 2px 5px;
 margin: 2px;
 border: 1px solid #000099;

 font-weight: bold;
 background-color: #000099;
 color: #FFF;
}
div.pagination span.disabled {
 padding: 2px 5px 2px 5px;
 margin: 2px;
 border: 1px solid #EEE;

 color: #DDD;
}

Download Source ( size 2.6 kB)

Firstly, I have created example xml file as songs.xml like :

<?xml version="1.0" encoding="ISO-8859-1"?>

<currentsongs>
<song>
<title>Song Title One</title>
<artist>artist name</artist>

</song>

<song>
<title>Song Title Two</title>
<artist>Sec artist name</artist>

</song>
</currentsongs>

Then in php file :

<?php

$objDOM = new DOMDocument();
$objDOM->load("songs.xml"); //make sure path is correct

$songs = $objDOM->getElementsByTagName("song");

foreach( $songs as $value )
{
$title = $value->getElementsByTagName("title");
$song_title  = $title->item(0)->nodeValue;

$artist = $value->getElementsByTagName("artist");
$artist_name  = $artist->item(0)->nodeValue;

echo "$song_title - $artist_name <br>";
}

?>

Download Source ( size 868 B)