A Simple Pagination, is it okay?

[Sanjib Sinha]

I tried a simple pagination. As a web hobbyist, i tried to visualize the whole aspect first, and then tried to implement them. I need experts opinion. Is my approach okay? How i can i modify it (i am sure it is too simple an approach, and can be modified)?

 

1) i keep an MyArray class at my lib folder and name it commonfunction.php. it goes like this:

class myArray implements ArrayAccess {

    protected $array = array();

    function  offsetSet($offset, $value) {
        if(!is_numeric($offset)){
            throw new Exception("Invalid key {$offset}") ;
        }
        $this->array[$offset] = $value;
    }

    function  offsetGet($offset) {
        return $this->array[$offset];
    }

    function  offsetUnset($offset) {
        unset ($this->array[$offset]);
    }

    function  offsetExists($offset) {
        return array_key_exists($this->array, $offset);
    }

}

2) Next, i have a published comments table, that i want to paginate. To start with, i create a pagination1.php page. The code is like this:

<?php
include_once 'lib/commonfunction.php';

if(!isset ($_REQUEST['next'])){
        echo "";
    }
    
mysql_connect('localhost', 'root', '');
mysql_select_db('appababa');

//////////////////////////////////////////////////////////////////////////////////
//trying pagination///
$myrow = new myArray();
$myquery = mysql_query("SELECT * FROM comments WHERE `comments`.`is_published`='Y'");
$myresults = array();
while ($myrow = mysql_fetch_array($myquery)) {
    $myresults[]=$myrow[0];
}  
    
foreach ($myresults as $key=>$value) {  
    
    $myquery = mysql_query("SELECT * FROM comments WHERE `comments`.`id`='".$value."'");
    while ($fullrow = mysql_fetch_array($myquery)) {
        //echo "Description : ".$fullrow['description']."<br>";
            if ($fullrow['id']==1){
                echo "Description : ".$fullrow['description']."<br>";
                $next=next($fullrow);
                $next++;
                echo "<a href='http://localhost/ClassesAndObjects/pagination2.php?next={$next}'>NEXT</a>";
            }
    }
}
?>

3) Next i have a pagination2.php. The code is like this:

<?php
include_once 'lib/commonfunction.php';

if(!isset ($_REQUEST['next'])){
        echo "";
    }

mysql_connect('localhost', 'root', '');
mysql_select_db('appababa');

//////////////////////////////////////////////////////////////////////////////////
//trying pagination///
$myrow = new myArray();
$myquery = mysql_query("SELECT * FROM comments WHERE `comments`.`is_published`='Y'");
$myresults = array();
while ($myrow = mysql_fetch_array($myquery)) {
    $myresults[]=$myrow[0];
}
$present=0;
if(isset ($_REQUEST['next']))
$present = $_REQUEST['next'];

if ($present==0){
    header('Location:http://localhost/ClassesAndObjects/pagination1.php');
}

$myquery = mysql_query("SELECT * FROM comments WHERE `comments`.`id`='".$present."'");

while ($fullrow = mysql_fetch_array($myquery)) {
        
        //echo "Description : ".$fullrow['description']."<br>";
            if ($fullrow['id']==$present){
                echo "Description : ".$fullrow['description']."<br>";
                
                $next=next($fullrow);
                $next++;
                echo "<a href='http://localhost/ClassesAndObjects/pagination2.php?next={$next}'>NEXT</a>";
                echo " ------ ";
                $prev=prev($fullrow);
                $prev--;
                echo "<a href='http://localhost/ClassesAndObjects/pagination3.php?prev={$prev}'>PREV</a>";
                
            }
    }
$row = new myArray();
$query1 = mysql_query("SELECT * FROM comments WHERE `comments`.`is_published`='Y'");
$results = array();
while ($row = mysql_fetch_array($query1)) {
    $results[]=$row[0];
    //echo $row['description']." = "."<a href='http://localhost/ClassesAndObjects/update.php?id={$row['id']}'>UNPUBLISH</a>"."<br>";
}

//echo "Total number of published comments : ".count($results);
$count=count($results);
$count++;
    if ($present==$count){
    header('Location:http://localhost/ClassesAndObjects/pagination1.php');
}

?>

3) Next i have pagination3.php. The code is like this:

<?php
include_once 'lib/commonfunction.php';

if(!isset ($_REQUEST['prev'])){
        echo "";
    }

mysql_connect('localhost', 'root', '');
mysql_select_db('appababa');

//////////////////////////////////////////////////////////////////////////////////
//trying pagination///
$myrow = new myArray();
$myquery = mysql_query("SELECT * FROM comments WHERE `comments`.`is_published`='Y'");
$myresults = array();
while ($myrow = mysql_fetch_array($myquery)) {
    $myresults[]=$myrow[0];
}
$present=0;
if(isset ($_REQUEST['prev']))
$present = $_REQUEST['prev'];

if ($present==0){
    header('Location:http://localhost/ClassesAndObjects/pagination1.php');
}

$myquery = mysql_query("SELECT * FROM comments WHERE `comments`.`id`='".$present."'");
    while ($fullrow = mysql_fetch_array($myquery)) {
        //echo "Description : ".$fullrow['description']."<br>";
            if ($fullrow['id']==$present){
                echo "Description : ".$fullrow['description']."<br>";

                $next=next($fullrow);
                $next++;
                echo "<a href='http://localhost/ClassesAndObjects/pagination2.php?next={$next}'>NEXT</a>";
                echo " ------ ";
                $prev=prev($fullrow);
                $prev--;
                echo "<a href='http://localhost/ClassesAndObjects/pagination3.php?prev={$prev}'>PREV</a>";

            }
    }

?>

Finally, it works faultlessly. There is apparently no problem. It is based on mainly three array functions, count(), next(), and prev(). I tried to avoid mathematical calculation as much as possible. 

 

I need your opinion. Many thanks.

[Sanjib Sinha]

Any advice please? usually pagination being done by calculating LIMIT in sql code. i tried to avoid that mathematical calculation depending mainly on three array functions. 

can this approach be encapsulated in a class? or i should take any other approach to solve this problem?

[trq]

usually pagination being done by calculating LIMIT in sql code. i tried to avoid that mathematical calculation depending mainly on three array functions.

Why? Your are now querying the database for more data than you use.

[Sanjib Sinha]

many thanks trk.

it was probably my bad English sentence construction, that changed the actual meaning for what i actually wanted to mean.

i wanted to say, when i query the database, there is always a LIMIT. when i paginate, that LIMIT either reduces or decreases and to capture that fine balance you need to use some mathematical functions.

i just downloaded an available pagination class and found, that array functions are not used at all! 

may be that is the correct approach. i feel slightly confused in that regard.

[trq]

I didn't really look at your code earlier, but there is definitely no limit clauses in your queries.

 

You might also want to take a look at what mysql_fetch_array actually returns, I think you might be confused. It only ever returns a single record.