Question

I am having trouble with modifying a php application to have pagination. My error seems to be with my logic, and I am not clear exactly what I am doing incorrectly. I have had before, but am not currently getting errors that mysql_num_rows() not valid result resource and that invalid arguments were supplied to foreach. I think there is a problem in my logic which is stopping the results from mysql from being returned.

All my ‘test’ echos are output except testing while loop. A page is generated with the name of the query and the word auctions, and first and previous links, but not the next and last links. I would be grateful if a more efficient way of generating links for the rows in my table could be pointed out, instead of making a link per cell. Is it possible to have a continuous link for several items?

<?php if (isset($_GET['cmd']))   $cmd = $_GET['cmd']; else die('You should have a 'cmd' parameter in your URL'); $query =''; if (isset($_GET['query'])) {     $query = $_GET['query']; } if (isset($_GET['pg'])) {   $pg = $_GET['pg'];  }   else $pg = 1; $con = mysql_connect('localhost','user','password'); echo 'test connection<p>'; if(!$con) {     die('Connection failed because of' .mysql_error()); } mysql_query('SET NAMES utf8'); mysql_select_db('database',$con); if($cmd=='GetRecordSet'){     echo 'test in loop<p>';      $table = 'SaleS';     $page_rows = 10;     $max = 'limit ' .($pg - 1) * $page_rows .',' .$page_rows;     $rows = getRowsByProductSearch($query, $table, $max);     echo 'test after query<p>';     $numRows = mysql_num_rows($rows);     $last = ceil($rows/$page_rows);     if ($pg < 1) {         $pg = 1;     } elseif ($pg > $last) {         $pg = $last;     }     echo 'html stuff <p>';      foreach ($rows as $row) {  echo 'test foreach <p>';         $pk = $row['Product_NO'];         echo '<tr>' . '\n';         echo '<td><a href='#' onclick='updateByPk(\'Layer2\', \'' . $pk . '\')'>'.$row['USERNAME'].'</a></td>' . '\n';         echo '<td><a href='#' onclick='updateByPk(\'Layer2\', \'' . $pk . '\')'>'.$row['shortDate'].'</a></td>' . '\n';         echo '<td><a href='#' onclick='updateByPk(\'Layer2\', \'' . $pk . '\')'>'.$row['Product_NAME'].'</a></td>' . '\n';         echo '</tr>' . '\n';     }     if ($pg == 1) {     } else {         echo ' <a href='{$_SERVER['PHP_SELF']}?pg=1'> <<-First</a> ';         echo ' ';         $previous = $pg-1;         echo ' <a href='{$_SERVER['PHP_SELF']}?pg=$previous'> <-Previous</a> ';     }     echo '---------------------------';     if ($pg == $last) {     } else {         $next = $pg+1;         echo ' <a href='{$_SERVER['PHP_SELF']}?pg=$next'>Next -></a> ';         echo ' ';         echo ' <a href='{$_SERVER['PHP_SELF']}?pg=$last'>Last ->></a> ';     }     echo '</table>\n'; } echo '</div>'; function getRowsByProductSearch($searchString, $table, $max) {     $searchString = mysql_real_escape_string($searchString);     $result = mysql_query('SELECT Product_NO, USERNAME, ACCESSSTARTS, Product_NAME, date_format(mycolumn, '%d %m %Y') as shortDate FROM {$table} WHERE upper(Product_NAME) LIKE '%' . $searchString . '%'' . $max);     if($result === false) {         echo mysql_error();     }     $rows = array();     while($row = mysql_fetch_assoc($result)) {         echo 'test while <p>';         $rows[] = $row;     }     return $rows;     mysql_free_result($result); } 

edit: I have printed out the mysql error of which there was none. However 8 ‘test whiles’ are printed out, from a database with over 100 records. The foreach loop is never entereded, and I am unsure why.

Answer 1

The problem (or at least one of them) is in the code that reads:

$rows = getRowsByProductSearch($query, $table, $max); $numRows = mysql_num_rows($rows); 

The $numRows variable is not a MySQL resultset, it is just a normal array returned by getRowsByProductSearch.

Change the code to read:

$rows = getRowsByProductSearch($query, $table, $max); $numRows = count($rows); 

Then it should at least find some results for you.

Good luck, James

Hi there,

The next problem is with the line that reads:

$last = ceil($rows/$page_rows); 

It should be changed to read:

$last = ceil($numRows / $page_rows); 

Would recommend adding the following lines to the start of you script at least while debugging:

ini_set('error_reporting', E_ALL | E_STRICT); ini_set('display_errors', 'On'); 

As that would have thrown up a fatal error and saved you a whole lot of time.