Use of “Next” and “Previous” in pagination

Question

I am using the following snippet. The next button works as it should but when all results have been shown and when there is nothing more to show, the next button still shows. Here is what i am using:

  //check if the starting row variable was passed in the URL or not
 if (!isset($_GET['pg']) or !is_numeric($_GET['pg'])) {
//we give the value of the starting row to 0 because nothing was found in URL
  $startrow = 0;
 //otherwise we take the value from the URL
  } else {
 $startrow = (int)mysql_real_escape_string($_GET['pg']);
}



 if($num_rows > 10) {
 echo 'next';
 } 

 $prev = $startrow - 10;

 //only print a "Previous" link if a "Next" was clicked
if ($prev >= 0) {
echo 'previous';

 }

Answer 1

To determine if you want to display the next button, you must know the total number of page, and compare it to the current page index.

$itemPerPage = 10;
$firstPage = 0; // or 1, depending on your implementation
$totalPage = ceil($num_rows / $itemPerPage);
$currentPage = (int)$_GET['pg'];
if($currentPage > $firstPage)
   echo 'prev';

if($currentPage < $totalPage)
   echo 'next';

In your case, make sure you don't mess up between a page, and an item number, because a page will probably display many items.

Answer 2

Try something like this:

<?php
// database connection info
$conn = mysql_connect('localhost','dbusername','dbpass') or trigger_error("SQL", E_USER_ERROR);
$db = mysql_select_db('dbname',$conn) or trigger_error("SQL", E_USER_ERROR);

// find out how many rows are in the table 
$sql = "SELECT COUNT(*) FROM numbers";
$result = mysql_query($sql, $conn) or trigger_error("SQL", E_USER_ERROR);
$r = mysql_fetch_row($result);
$numrows = $r[0];

// number of rows to show per page
$rowsperpage = 10;
// find out total pages
$totalpages = ceil($numrows / $rowsperpage);

// get the current page or set a default
if (isset($_GET['currentpage']) && is_numeric($_GET['currentpage'])) {
   // cast var as int
   $currentpage = (int) $_GET['currentpage'];
} else {
   // default page num
   $currentpage = 1;
} // end if

// if current page is greater than total pages...
if ($currentpage > $totalpages) {
   // set current page to last page
   $currentpage = $totalpages;
} // end if
// if current page is less than first page...
if ($currentpage < 1) {
   // set current page to first page
   $currentpage = 1;
} // end if

// the offset of the list, based on current page 
$offset = ($currentpage - 1) * $rowsperpage;

// get the info from the db 
$sql = "SELECT id, number FROM numbers LIMIT $offset, $rowsperpage";
$result = mysql_query($sql, $conn) or trigger_error("SQL", E_USER_ERROR);

// while there are rows to be fetched...
while ($list = mysql_fetch_assoc($result)) {
   // echo data
   echo $list['id'] . " : " . $list['number'] . "<br />";
} // end while

/******  build the pagination links ******/
// range of num links to show
$range = 3;

// if not on page 1, don't show back links
if ($currentpage > 1) {
   // show << link to go back to page 1
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=1'><<</a> ";
   // get previous page num
   $prevpage = $currentpage - 1;
   // show < link to go back to 1 page
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$prevpage'><</a> ";
} // end if 

// loop to show links to range of pages around current page
for ($x = ($currentpage - $range); $x < (($currentpage + $range) + 1); $x++) {
   // if it's a valid page number...
   if (($x > 0) && ($x <= $totalpages)) {
      // if we're on current page...
      if ($x == $currentpage) {
         // 'highlight' it but don't make a link
         echo " [<b>$x</b>] ";
      // if not current page...
      } else {
         // make it a link
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$x'>$x</a> ";
      } // end else
   } // end if 
} // end for

// if not on last page, show forward and last page links    
if ($currentpage != $totalpages) {
   // get next page
   $nextpage = $currentpage + 1;
    // echo forward link for next page 
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$nextpage'>></a> ";
   // echo forward link for lastpage
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$totalpages'>>></a> ";
} // end if
/****** end build pagination links ******/
?>

Answer 3

Considering the number of times you've asked this very same question, I highly recommend you study PHP Pagination.

PHP Freaks has a decent tutorial.

How to Paginate Data with PHP really breaks it down and builds a class.

Basic PHP and MySQL Pagination Tutorial is fairly standard.

There are 190,000 Google results for the search phrase “php mysql pagination tutorial”

Have fun and good luck!

Answer 4

Maybe this php pagination class could be useful for you

Regards.