Tuesday, January 22, 2008

Database & Paging

******************* Db.php

$dbhost = 'localhost';
$dbuser = 'root';
$dbpass = '';
$dbname = 'mydatabase';
$conn = mysql_connect ($dbhost, $dbuser, $dbpass) or die ('I cannot connect to the database because: ' . mysql_error());
mysql_select_db ($dbname);
?>
****************************** Paging *****************************



<html>

<head>

<title>Implementing Paging with next and prev</title>

<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">

</head>



<body>

<?php

include 'library/config.php';

include 'library/opendb.php';



// how many rows to show per page

$rowsPerPage = 3;



// by default we show first page

$pageNum = 1;



// if $_GET['page'] defined, use it as page number

if(isset($_GET['page']))

{

$pageNum = $_GET['page'];

}



// counting the offset

$offset = ($pageNum - 1) * $rowsPerPage;



$query = "SELECT val FROM randoms LIMIT $offset, $rowsPerPage";

$result = mysql_query($query) or die('Error, query failed');



// print the random numbers

while($row = mysql_fetch_array($result))

{

echo $row['val'] . '<br>';

}

echo '<br>';



// how many rows we have in database

$query = "SELECT COUNT(val) AS numrows FROM randoms";

$result = mysql_query($query) or die('Error, query failed');

$row = mysql_fetch_array($result, MYSQL_ASSOC);

$numrows = $row['numrows'];



// how many pages we have when using paging?

$maxPage = ceil($numrows/$rowsPerPage);



// print the link to access each page

$self = $_SERVER['PHP_SELF'];

$nav = '';

for($page = 1; $page <= $maxPage; $page++)

{

if ($page == $pageNum)

{

$nav .= " $page "; // no need to create a link to current page

}

else

{

$nav .= " <a href=\"$self?page=$page\">$page</a> ";

}

}



// creating previous and next link

// plus the link to go straight to

// the first and last page



if ($pageNum > 1)

{

$page = $pageNum - 1;

$prev = " <a href=\"$self?page=$page\">[Prev]</a> ";



$first = " <a href=\"$self?page=1\">[First Page]</a> ";

}

else

{

$prev = '&nbsp;'; // we're on page one, don't print previous link

$first = '&nbsp;'; // nor the first page link

}



if ($pageNum < $maxPage)

{

$page = $pageNum + 1;

$next = " <a href=\"$self?page=$page\">[Next]</a> ";



$last = " <a href=\"$self?page=$maxPage\">[Last Page]</a> ";

}

else

{

$next = '&nbsp;'; // we're on the last page, don't print next link

$last = '&nbsp;'; // nor the last page link

}



// print the navigation link

echo $first . $prev . $nav . $next . $last;



// and close the database connection

include 'library/closedb.php';

?>

</body>

</html>

 

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