How to manage PHP page

philippeponceblanc · November 10, 2017, 8:54pm

Hello,
I developed a program with MySql, so I have an output with the query “select” but the result displays a long html page.
I would like to know how to manage the display of pages with a small menu page 1, page 2, page 3, etc …
by searching on the net I realized with the method $ _GET we can return the page number!
I’m using MySql, I’m not querying error!
I wrote this program that a chat with a date, a nickname and a message that should appear in an HTML table, I do not understand my script returns a blank page.
Sorry comments are in French!

Here is an excerpt from my code

<?php
// Connexion à la base de données
$messagesParPage=10;
//$premiereEntree=0;
//$total=0;
try
{
	$bdd = new PDO('mysql:host=localhost;dbname=test;charset=utf8', 'root', '');
}
catch(Exception $e)
{
        die('Erreur : '.$e->getMessage());
}

$retour_total=mysql_query('SELECT COUNT(*) AS total FROM minichat'); //Nous récupérons le contenu de la requête dans $retour_total
$donnees_total=mysql_fetch_assoc($retour_total); //On range retour sous la forme d'un tableau.
$total=$donnees_total['total'];
$nombreDePages=ceil($total/$messagesParPage);


 
if(isset($_GET['page'])) // Si la variable $_GET['page'] existe...
{
     $pageActuelle=intval($_GET['page']);
 
     if($pageActuelle>$nombreDePages) // Si la valeur de $pageActuelle (le numéro de la page) est plus grande que $nombreDePages...
     {
          $pageActuelle=$nombreDePages;
     }
}
else // Sinon
{
     $pageActuelle=1; // La page actuelle est la n°1    
}

$premiereEntree=($pageActuelle-1)*$messagesParPage;


$retour_messages=mysql_query('SELECT pseudo, message, DATE_FORMAT(date_message, \'%d/%m/%Y à %Hh%imin\') AS date_message_fr FROM minichat ORDER BY ID DESC LIMIT '.$premiereEntree.', '.$messagesParPage.'');
 
while($donnees_messages=mysql_fetch_assoc($retour_messages))
{
 echo '<table width="400" border="0" align="center" cellpadding="0" cellspacing="0">
             
                <tr>
                    <td><strong> Date : '.(htmlspecialchars($donnees_messages['date_message_fr']).'</strong></td>
                </tr>
                <tr>
                     <td><strong> Ecrit par : '.(htmlspecialchars($donnees_messages['pseudo'])).'</strong></td>
                </tr>
                <tr>   
                   <td><strong> Message :  '.(htmlspecialchars($donnees_messages['message'])).'</strong></p></dt>
                </tr>   
        </table><br /><br />';
}

 echo '<p align="center">Page : '; //Pour l'affichage, on centre la liste des pages
for($i=1; $i<=$nombreDePages; $i++) //On fait notre boucle
{
     //On va faire notre condition
     if($i==$pageActuelle) //Si il s'agit de la page actuelle...
     {
         echo ' [ '.$i.' ] '; 
     }	
     else //Sinon...
     {
          echo ' <a href="minichat.php?page='.$i.'">'.$i.'</a> ';
     }
}
echo '</p>';
$reponse->closeCursor();
?>

Best Regards
Philippe

benanamen · November 10, 2017, 11:00pm

Your biggest problem is that you are mixing dangerous obsolete mysql_* code with PDO. Study this tutorial on PDO to learn how to use it properly. https://phpdelusions.net/pdo

philippeponceblanc · November 11, 2017, 4:08pm

hi Benanamen,

after reading your PDO tutorial, which is well done i thought about modifying my code,
here is my code, but I did not understand the two variables $ offset and $ limit which are parametres essenciel

<?php
// Connexion à la base de données
$messagesParPage=10;
//$premiereEntree=0;
//$total=0;
try
{
	$bdd = new PDO('mysql:host=localhost;dbname=test;charset=utf8', 'root', 'dacashAc3');
}
catch(Exception $e)
{
        die('Erreur : '.$e->getMessage());
}

$retour_total=mysql_query('SELECT COUNT(*) AS total FROM minichat'); //Nous récupérons le contenu de la requête dans $retour_total
$donnees_total=mysql_fetch_assoc($retour_total); //On range retour sous la forme d'un tableau.
$total=$donnees_total['total'];
$nombreDePages=ceil($total/$messagesParPage);


 
if(isset($_GET['page'])) // Si la variable $_GET['page'] existe...
{
     $pageActuelle=intval($_GET['page']);
 
     if($pageActuelle>$nombreDePages) // Si la valeur de $pageActuelle (le numéro de la page) est plus grande que $nombreDePages...
     {
          $pageActuelle=$nombreDePages;
     }
}
else // Sinon
{
     $pageActuelle=1; // La page actuelle est la n°1    
}

$premiereEntree=($pageActuelle-1)*$messagesParPage;



$conn -> setAttribute ( PDO :: ATTR_EMULATE_PREPARES , false ); 
$stmt = $pdo->prepare('SELECT pseudo, message, DATE_FORMAT(date_message, \'%d/%m/%Y à %Hh%imin\') AS date_message_fr FROM minichat ORDER BY ID DESC LIMIT ?,?');
$stmt -> execute ([ $premiereEntree ,$retour_total  ]); 
$data = $stmt->fetchAll();
while ($data = $stmt->fetch()))
{
 echo '<table width="400" border="0" align="center" cellpadding="0" cellspacing="0">
             
                <tr>
                    <td><strong> Date : '.(htmlspecialchars($data['date_message_fr']).'</strong></td>
                </tr>
                <tr>
                     <td><strong> Ecrit par : '.(htmlspecialchars($data['pseudo'])).'</strong></td>
                </tr>
                <tr>   
                   <td><strong> Message :  '.(htmlspecialchars($data['message'])).'</strong></p></dt>
                </tr>   
        </table><br /><br />';
}

 echo '<p align="center">Page : '; //Pour l'affichage, on centre la liste des pages
for($i=1; $i<=$nombreDePages; $i++) //On fait notre boucle
{
     //On va faire notre condition
     if($i==$pageActuelle) //Si il s'agit de la page actuelle...
     {
         echo ' [ '.$i.' ] '; 
     }	
     else //Sinon...
     {
          echo ' <a href="minichat.php?page='.$i.'">'.$i.'</a> ';
     }
}
echo '</p>';
$reponse->closeCursor();
?>

benanamen · November 11, 2017, 4:31pm

You did not modify your code. You see this: mysql_query and this: mysql_fetch_assoc? That is not PDO. That is obsolete mysql.

droopsnoot · November 11, 2017, 7:13pm

These are the start record number and number of records per page for your search, and you’ll pass them in using the “next page” and “previous page” links. So for example, when you first execute the code these will default to 0 and, say, 10. You’ll draw the first ten results, and you’ll draw a link to the next page, which will include variables to set the offset to 11, so it does the next page. When you draw the second page, you’ll have a link for offset=0 (for previous page) and one with offset=21, for next page. And so on. You probably don’t need to pass limit as the page size will probably stay the same.

If you’re just passing a page number as part of the link, then you can calculate offset by multiplying the number of records per page by the page number.

philippeponceblanc · November 11, 2017, 8:17pm

so I thought about doing like this code below

<?php
// Connexion à la base de données
$messagesParPage=10;
//$premiereEntree=0;
//$total=0;
try
{
	$bdd = new PDO('mysql:host=localhost;dbname=test;charset=utf8', 'root', 'toto');
}
catch(Exception $e)
{
        die('Erreur : '.$e->getMessage());
}


$conn -> setAttribute ( PDO :: ATTR_EMULATE_PREPARES , false );  
$retour_total = $pdo->prepare('SELECT COUNT(*) AS total FROM minichat') ;
$total=$donnees_total=-> execute ([$retour_total]);



$nombreDePages=ceil($total/$messagesParPage);


 
if(isset($_GET['page'])) // Si la variable $_GET['page'] existe...
{
     $pageActuelle=intval($_GET['page']);
 
     if($pageActuelle>$nombreDePages) // Si la valeur de $pageActuelle (le numéro de la page) est plus grande que $nombreDePages...
     {
          $pageActuelle=$nombreDePages;
     }
}
else // Sinon
{
     $pageActuelle=1; // La page actuelle est la n°1    
}

$premiereEntree=($pageActuelle-1)*$messagesParPage;


//$retour_messages=mysql_query('SELECT pseudo, message, DATE_FORMAT(date_message, \'%d/%m/%Y à %Hh%imin\') AS date_message_fr FROM minichat ORDER BY ID DESC LIMIT '.$premiereEntree.', '.$messagesParPage.'');
$conn -> setAttribute ( PDO :: ATTR_EMULATE_PREPARES , false ); 
$stmt = $pdo->prepare('SELECT pseudo, message, DATE_FORMAT(date_message, \'%d/%m/%Y à %Hh%imin\') AS date_message_fr FROM minichat ORDER BY ID DESC LIMIT ?,?');
$stmt -> execute ([ $premiereEntree ,$retour_total  ]); 
$data = $stmt->fetchAll();
while ($data = $stmt->fetch()))
{
 echo '<table width="400" border="0" align="center" cellpadding="0" cellspacing="0">
             
                <tr>
                    <td><strong> Date : '.(htmlspecialchars($data['date_message_fr']).'</strong></td>
                </tr>
                <tr>
                     <td><strong> Ecrit par : '.(htmlspecialchars($data['pseudo'])).'</strong></td>
                </tr>
                <tr>   
                   <td><strong> Message :  '.(htmlspecialchars($data['message'])).'</strong></p></dt>
                </tr>   
        </table><br /><br />';
}

 echo '<p align="center">Page : '; //Pour l'affichage, on centre la liste des pages
for($i=1; $i<=$nombreDePages; $i++) //On fait notre boucle
{
     //On va faire notre condition
     if($i==$pageActuelle) //Si il s'agit de la page actuelle...
     {
         echo ' [ '.$i.' ] '; 
     }	
     else //Sinon...
     {
          echo ' <a href="minichat.php?page='.$i.'">'.$i.'</a> ';
     }
}
echo '</p>';
$reponse->closeCursor();
?>

for droopsboot
I think that a piece of code added by a multiplication of variable will be more concrete than writings, here is the problem that you say that is a list of the array will grow indefinitely, I tencose that $ offset was an interval I I’m aware of it from your explanation, but if you can translate it into lines of code it will be more efficient.

What do you think about this benanamen ?

also I’m happy to be on this site because the french reason is not to transfer

benanamen · November 11, 2017, 10:17pm

Run this. I think you will like it much better. You can modify to suit your needs.

<!DOCTYPE html>

<html>

<head>
  <title></title>

  <script src="https:///code.jquery.com/jquery-1.12.4.js"></script>
  <script src="https:///cdn.datatables.net/1.10.16/js/jquery.dataTables.min.js"></script>
  <script src="https:///cdn.datatables.net/1.10.16/js/dataTables.bootstrap.min.js"></script>
  <link rel="stylesheet" type="text/css" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
  <link rel="stylesheet" type="text/css" href="https://cdn.datatables.net/1.10.16/css/dataTables.bootstrap.min.css">

 <script>
 $(document).ready(function() {
    $('#example').DataTable();
} );
 </script>
</head>

<body>

<table id="example" class="table table-striped table-bordered" cellspacing="0" width="100%">
        <thead>
            <tr>
                <th>Name</th>
                <th>Position</th>
                <th>Office</th>
                <th>Age</th>
                <th>Start date</th>
                <th>Salary</th>
            </tr>
        </thead>
        <tfoot>
            <tr>
                <th>Name</th>
                <th>Position</th>
                <th>Office</th>
                <th>Age</th>
                <th>Start date</th>
                <th>Salary</th>
            </tr>
        </tfoot>
        <tbody>
            <tr>
                <td>Tiger Nixon</td>
                <td>System Architect</td>
                <td>Edinburgh</td>
                <td>61</td>
                <td>2011/04/25</td>
                <td>$320,800</td>
            </tr>
            <tr>
                <td>Garrett Winters</td>
                <td>Accountant</td>
                <td>Tokyo</td>
                <td>63</td>
                <td>2011/07/25</td>
                <td>$170,750</td>
            </tr>
            <tr>
                <td>Ashton Cox</td>
                <td>Junior Technical Author</td>
                <td>San Francisco</td>
                <td>66</td>
                <td>2009/01/12</td>
                <td>$86,000</td>
            </tr>
            <tr>
                <td>Cedric Kelly</td>
                <td>Senior Javascript Developer</td>
                <td>Edinburgh</td>
                <td>22</td>
                <td>2012/03/29</td>
                <td>$433,060</td>
            </tr>
            <tr>
                <td>Airi Satou</td>
                <td>Accountant</td>
                <td>Tokyo</td>
                <td>33</td>
                <td>2008/11/28</td>
                <td>$162,700</td>
            </tr>
            <tr>
                <td>Brielle Williamson</td>
                <td>Integration Specialist</td>
                <td>New York</td>
                <td>61</td>
                <td>2012/12/02</td>
                <td>$372,000</td>
            </tr>
            <tr>
                <td>Herrod Chandler</td>
                <td>Sales Assistant</td>
                <td>San Francisco</td>
                <td>59</td>
                <td>2012/08/06</td>
                <td>$137,500</td>
            </tr>
            <tr>
                <td>Rhona Davidson</td>
                <td>Integration Specialist</td>
                <td>Tokyo</td>
                <td>55</td>
                <td>2010/10/14</td>
                <td>$327,900</td>
            </tr>
            <tr>
                <td>Colleen Hurst</td>
                <td>Javascript Developer</td>
                <td>San Francisco</td>
                <td>39</td>
                <td>2009/09/15</td>
                <td>$205,500</td>
            </tr>
            <tr>
                <td>Sonya Frost</td>
                <td>Software Engineer</td>
                <td>Edinburgh</td>
                <td>23</td>
                <td>2008/12/13</td>
                <td>$103,600</td>
            </tr>
            <tr>
                <td>Jena Gaines</td>
                <td>Office Manager</td>
                <td>London</td>
                <td>30</td>
                <td>2008/12/19</td>
                <td>$90,560</td>
            </tr>
            <tr>
                <td>Quinn Flynn</td>
                <td>Support Lead</td>
                <td>Edinburgh</td>
                <td>22</td>
                <td>2013/03/03</td>
                <td>$342,000</td>
            </tr>
            <tr>
                <td>Charde Marshall</td>
                <td>Regional Director</td>
                <td>San Francisco</td>
                <td>36</td>
                <td>2008/10/16</td>
                <td>$470,600</td>
            </tr>
            <tr>
                <td>Haley Kennedy</td>
                <td>Senior Marketing Designer</td>
                <td>London</td>
                <td>43</td>
                <td>2012/12/18</td>
                <td>$313,500</td>
            </tr>
            <tr>
                <td>Tatyana Fitzpatrick</td>
                <td>Regional Director</td>
                <td>London</td>
                <td>19</td>
                <td>2010/03/17</td>
                <td>$385,750</td>
            </tr>
            <tr>
                <td>Michael Silva</td>
                <td>Marketing Designer</td>
                <td>London</td>
                <td>66</td>
                <td>2012/11/27</td>
                <td>$198,500</td>
            </tr>
            <tr>
                <td>Paul Byrd</td>
                <td>Chief Financial Officer (CFO)</td>
                <td>New York</td>
                <td>64</td>
                <td>2010/06/09</td>
                <td>$725,000</td>
            </tr>
            <tr>
                <td>Gloria Little</td>
                <td>Systems Administrator</td>
                <td>New York</td>
                <td>59</td>
                <td>2009/04/10</td>
                <td>$237,500</td>
            </tr>
            <tr>
                <td>Bradley Greer</td>
                <td>Software Engineer</td>
                <td>London</td>
                <td>41</td>
                <td>2012/10/13</td>
                <td>$132,000</td>
            </tr>
            <tr>
                <td>Dai Rios</td>
                <td>Personnel Lead</td>
                <td>Edinburgh</td>
                <td>35</td>
                <td>2012/09/26</td>
                <td>$217,500</td>
            </tr>
            <tr>
                <td>Jenette Caldwell</td>
                <td>Development Lead</td>
                <td>New York</td>
                <td>30</td>
                <td>2011/09/03</td>
                <td>$345,000</td>
            </tr>
            <tr>
                <td>Yuri Berry</td>
                <td>Chief Marketing Officer (CMO)</td>
                <td>New York</td>
                <td>40</td>
                <td>2009/06/25</td>
                <td>$675,000</td>
            </tr>
            <tr>
                <td>Caesar Vance</td>
                <td>Pre-Sales Support</td>
                <td>New York</td>
                <td>21</td>
                <td>2011/12/12</td>
                <td>$106,450</td>
            </tr>
            <tr>
                <td>Doris Wilder</td>
                <td>Sales Assistant</td>
                <td>Sidney</td>
                <td>23</td>
                <td>2010/09/20</td>
                <td>$85,600</td>
            </tr>
            <tr>
                <td>Angelica Ramos</td>
                <td>Chief Executive Officer (CEO)</td>
                <td>London</td>
                <td>47</td>
                <td>2009/10/09</td>
                <td>$1,200,000</td>
            </tr>
            <tr>
                <td>Gavin Joyce</td>
                <td>Developer</td>
                <td>Edinburgh</td>
                <td>42</td>
                <td>2010/12/22</td>
                <td>$92,575</td>
            </tr>
            <tr>
                <td>Jennifer Chang</td>
                <td>Regional Director</td>
                <td>Singapore</td>
                <td>28</td>
                <td>2010/11/14</td>
                <td>$357,650</td>
            </tr>
            <tr>
                <td>Brenden Wagner</td>
                <td>Software Engineer</td>
                <td>San Francisco</td>
                <td>28</td>
                <td>2011/06/07</td>
                <td>$206,850</td>
            </tr>
            <tr>
                <td>Fiona Green</td>
                <td>Chief Operating Officer (COO)</td>
                <td>San Francisco</td>
                <td>48</td>
                <td>2010/03/11</td>
                <td>$850,000</td>
            </tr>
            <tr>
                <td>Shou Itou</td>
                <td>Regional Marketing</td>
                <td>Tokyo</td>
                <td>20</td>
                <td>2011/08/14</td>
                <td>$163,000</td>
            </tr>
            <tr>
                <td>Michelle House</td>
                <td>Integration Specialist</td>
                <td>Sidney</td>
                <td>37</td>
                <td>2011/06/02</td>
                <td>$95,400</td>
            </tr>
            <tr>
                <td>Suki Burks</td>
                <td>Developer</td>
                <td>London</td>
                <td>53</td>
                <td>2009/10/22</td>
                <td>$114,500</td>
            </tr>
            <tr>
                <td>Prescott Bartlett</td>
                <td>Technical Author</td>
                <td>London</td>
                <td>27</td>
                <td>2011/05/07</td>
                <td>$145,000</td>
            </tr>
            <tr>
                <td>Gavin Cortez</td>
                <td>Team Leader</td>
                <td>San Francisco</td>
                <td>22</td>
                <td>2008/10/26</td>
                <td>$235,500</td>
            </tr>
            <tr>
                <td>Martena Mccray</td>
                <td>Post-Sales support</td>
                <td>Edinburgh</td>
                <td>46</td>
                <td>2011/03/09</td>
                <td>$324,050</td>
            </tr>
            <tr>
                <td>Unity Butler</td>
                <td>Marketing Designer</td>
                <td>San Francisco</td>
                <td>47</td>
                <td>2009/12/09</td>
                <td>$85,675</td>
            </tr>
            <tr>
                <td>Howard Hatfield</td>
                <td>Office Manager</td>
                <td>San Francisco</td>
                <td>51</td>
                <td>2008/12/16</td>
                <td>$164,500</td>
            </tr>
            <tr>
                <td>Hope Fuentes</td>
                <td>Secretary</td>
                <td>San Francisco</td>
                <td>41</td>
                <td>2010/02/12</td>
                <td>$109,850</td>
            </tr>
            <tr>
                <td>Vivian Harrell</td>
                <td>Financial Controller</td>
                <td>San Francisco</td>
                <td>62</td>
                <td>2009/02/14</td>
                <td>$452,500</td>
            </tr>
            <tr>
                <td>Timothy Mooney</td>
                <td>Office Manager</td>
                <td>London</td>
                <td>37</td>
                <td>2008/12/11</td>
                <td>$136,200</td>
            </tr>
            <tr>
                <td>Jackson Bradshaw</td>
                <td>Director</td>
                <td>New York</td>
                <td>65</td>
                <td>2008/09/26</td>
                <td>$645,750</td>
            </tr>
            <tr>
                <td>Olivia Liang</td>
                <td>Support Engineer</td>
                <td>Singapore</td>
                <td>64</td>
                <td>2011/02/03</td>
                <td>$234,500</td>
            </tr>
            <tr>
                <td>Bruno Nash</td>
                <td>Software Engineer</td>
                <td>London</td>
                <td>38</td>
                <td>2011/05/03</td>
                <td>$163,500</td>
            </tr>
            <tr>
                <td>Sakura Yamamoto</td>
                <td>Support Engineer</td>
                <td>Tokyo</td>
                <td>37</td>
                <td>2009/08/19</td>
                <td>$139,575</td>
            </tr>
            <tr>
                <td>Thor Walton</td>
                <td>Developer</td>
                <td>New York</td>
                <td>61</td>
                <td>2013/08/11</td>
                <td>$98,540</td>
            </tr>
            <tr>
                <td>Finn Camacho</td>
                <td>Support Engineer</td>
                <td>San Francisco</td>
                <td>47</td>
                <td>2009/07/07</td>
                <td>$87,500</td>
            </tr>
            <tr>
                <td>Serge Baldwin</td>
                <td>Data Coordinator</td>
                <td>Singapore</td>
                <td>64</td>
                <td>2012/04/09</td>
                <td>$138,575</td>
            </tr>
            <tr>
                <td>Zenaida Frank</td>
                <td>Software Engineer</td>
                <td>New York</td>
                <td>63</td>
                <td>2010/01/04</td>
                <td>$125,250</td>
            </tr>
            <tr>
                <td>Zorita Serrano</td>
                <td>Software Engineer</td>
                <td>San Francisco</td>
                <td>56</td>
                <td>2012/06/01</td>
                <td>$115,000</td>
            </tr>
            <tr>
                <td>Jennifer Acosta</td>
                <td>Junior Javascript Developer</td>
                <td>Edinburgh</td>
                <td>43</td>
                <td>2013/02/01</td>
                <td>$75,650</td>
            </tr>
            <tr>
                <td>Cara Stevens</td>
                <td>Sales Assistant</td>
                <td>New York</td>
                <td>46</td>
                <td>2011/12/06</td>
                <td>$145,600</td>
            </tr>
            <tr>
                <td>Hermione Butler</td>
                <td>Regional Director</td>
                <td>London</td>
                <td>47</td>
                <td>2011/03/21</td>
                <td>$356,250</td>
            </tr>
            <tr>
                <td>Lael Greer</td>
                <td>Systems Administrator</td>
                <td>London</td>
                <td>21</td>
                <td>2009/02/27</td>
                <td>$103,500</td>
            </tr>
            <tr>
                <td>Jonas Alexander</td>
                <td>Developer</td>
                <td>San Francisco</td>
                <td>30</td>
                <td>2010/07/14</td>
                <td>$86,500</td>
            </tr>
            <tr>
                <td>Shad Decker</td>
                <td>Regional Director</td>
                <td>Edinburgh</td>
                <td>51</td>
                <td>2008/11/13</td>
                <td>$183,000</td>
            </tr>
            <tr>
                <td>Michael Bruce</td>
                <td>Javascript Developer</td>
                <td>Singapore</td>
                <td>29</td>
                <td>2011/06/27</td>
                <td>$183,000</td>
            </tr>
            <tr>
                <td>Donna Snider</td>
                <td>Customer Support</td>
                <td>New York</td>
                <td>27</td>
                <td>2011/01/25</td>
                <td>$112,000</td>
            </tr>
        </tbody>
    </table>

</body>
</html>

philippeponceblanc · November 11, 2017, 10:47pm

yes I executed the code very good result is nice!
but alas I have to write PHP / mysql no script jquery!
the course I follow is MySql Data Extraction!
it is necessary to learn this algorithm to be able to wear it in Java EE for example.
it reminds me of the processing of an xml file …
but I am not allowed to use funtions hosted on sites.
I know perfectly well that there is plenty of resources for an identical result with a pager.
But alas I am bound to use PHP / Mysql only!
Say I have no choice of the technology used.

system · February 11, 2018, 5:48am

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