Paging a Dynamic Selectbox in different php files

Question

Good afternoon, I am facing a problem in creating a pagination.

Javascript

    <script type="text/javascript">
        $(document).ready(function(){
            $('#estados').on('change', function(e){
                var estado = document.getElementById('estados')
                var estadovl = document.getElementById('estadovl')
                estadovl.value = estado.options[estado.selectedIndex].value
            });
        });
</script>

HTML - Page 1

<div class="container">
    <div class="row">
        <div class="col-xs-4 col-xs-offset-4"> 
            <h1>Cidade Escolha</h1>
            <form class="text-center" method="get" enctype="application/x-www-form-urlencoded" id="form1" action='cidades.php'>
                <div class="form-group">

                    <select class="form-control" id="estados" name="estados">
                        <option>Escolha seu Estado</option>
                        <?php 
                            $query = "select * from estados;";
                            $dt = mysqli_query($conn, $query);
                            while ($row = mysqli_fetch_array($dt)){
                            ?>
                            <option value="<?php echo $row['estado_id'];?>"><?php echo $row['nome'];?></option>
                            <?php }; ?>

                   <input type="text" id="estadovl" name="estadovl" hidden="hidden">
                 </select>

                    <input type="submit" name="submit" id="submit" placeholder="enviar">
                </div>
            </form>
        </div>
    </div>  
</div>






    <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>



    <script src="js/bootstrap.min.js"></script>                   

Already connected with the database, on the first page the client will choose a Brazilian state (states are stored in mysql), the value of the option will be played to the <input type="text" id="estadovl" name="estadovl" hidden="hidden"> as mentioned in the javascript code and will be redirected to page 2.

PHP - Page 2

include ('conection.php'); 

/*if(isset($_GET['page'])){
    $page = $_GET['page'];
}else{
    $page = 1;
}*/

$numpag = 10;
$pagina = (isset( $_GET['pagina'])) ? $_GET['pagina'] : 1;
$inicio = $pagina * $numpag;




$query = "SELECT * FROM cidades WHERE estado_id = ".$_GET['estadovl']." AND status = 1 ORDER BY nome ASC LIMIT $inicio,$numpag";
$dt = mysqli_query($conn, $query);
$rowcount = mysqli_num_rows($dt);

On this page, he will find all the cities belonging to the chosen state. Cities (which are also stored in the database) are shown in the above code. It turns out I have to make a pagination limiting 10 cities per page, but this "cities.php" doesn’t open as "cities.php? page=1" as changed in variable $pagina = (isset( $_GET['pagina'])) ? $_GET['pagina'] : 1;, in addition, the "span link" states that the state has not been chosen.

<h1>Cidade Escolha</h1>
  <div class="row">
    <?php while($row = mysqli_fetch_array($dt)){?>
      <div class='col-xs-12 col-md-6'>
        <div class='panel panel-default'>
          <div class='panel-title'>
            <h2 style='text-align:center;'><?php echo $row['nome']; ?></h2>
          </div>
          <div class='panel-body'>
            <p><h3>Lorem Ipsum</h3></p>
            <p>Endereço: <?php echo $row['cep'] ?></p>
            <p>Telefone:</p>      
          </div>
        </div> 
      </div>
    <?php } ?>
  </div>
  <div class="pull-left">
    <span>
      <?php
        $pgquery = "SELECT * FROM cidades WHERE estado_id = ".$_GET['estadovl']." AND status = 1 ORDER BY nome ASC;";
        $pgdt = mysqli_query($conn, $pgquery);
        $pgrowcount = mysqli_num_rows($pgdt); 
        $totalpag = ceil($pgrowcount/$numpag);
        for($i = 1; $i<= $totalpag; $i++){
          echo "<a href='cidades.php?page=".$i."'>$i</a>";
        }
      ?>
    </span>
  </div>

Answer 1

Well before anything else I recommend you to do some research on sql Injection

I took a look at your code and I think it might help:

• Taking into account that when you navigate to the page cidades.php, you already have the value estado by the variable $_GET['estadovl']

In the observation you say that the results are skipping the first 10 records, this is because its variable $inicio begins of 10 and not of 0, change this code on page 2 should already resolve this issue:

// De 
$inicio = $pagina * $numpag;

// Para
$inicio = ( $pagina - 1 ) * $numpag;

About the pagination I advise you to add the status along with the link to the page

// De
echo "<a href='cidades.php?page=".$i."'>$i</a>"; 

// Para
echo "<a href='cidades.php?page=".$i."&estadovl=".$_GET['estadovl']."'>$i</a>"; 

Answer 2

Well, from what I see in the prints, the problem is in the states. You have to pass the state parameter to get the $_GET['estadovl']. Your URL has to stay http://.../cities.php? pagina=1&estadovl=MG It’s missing change in this place here too:

  for($i = 1; $i<= $totalpag; $i++){
          echo "<a href='cidades.php?page=".$i."'>$i</a>";
        }

Must be something like:

 for($i = 1; $i<= $totalpag; $i++){
              echo "<a href='cidades.php?page=".$i."'&estadovl=".$_GET['estadovl'].">$i</a>";
            }