如何在刷新后保留页面中变量的值

I have a search page and the pagination is set but each time i refresh the search variable sets back to default... It also restores to default if i try to navigate to within pagination... So i want to know how to keep the value of the search variable...

The search form is in another page.

I have tried using this session_start() method but it doesn't seem to retain the search variable...

<?php require_once("../includes/initialize.php"); ?>
<?php
             session_start();
        if(isset($_POST['submit'])){
        // 1. the current page number ($current_page)
        $page = !empty($_GET['page']) ? (int)$_GET['page'] : 1;
        // 2. records per page ($per_page)
        $per_page = 2;
        // 3. total record count ($total_count)
        $_SESSION['search'] = $_POST['search'];
        echo $_SESSION['search'];   
        $search = $database->escape_value($_SESSION['search']);

        $sql  = "SELECT COUNT(*) FROM products WHERE image LIKE '%$search%'";
        $sql .= " OR title LIKE '%$search%'";
        $sql .= " OR slug LIKE '%$search%'";
        $sql .= " OR description LIKE '%$search%'";
        $sql .= " OR price LIKE '%$search%'";
        $sql = $database->query($sql);
        $sql = $database->fetch_array($sql);
        $total_count = array_shift($sql); 

        // Find all photos
        // use pagination instead
        $pagination = new Pagination($page, $per_page, $total_count);
        // Instead of finding all records, just find the records

        $sql  = "SELECT * FROM products WHERE image LIKE '%$search%'";
        $sql .= " OR title LIKE '%$search%'";
        $sql .= " OR slug LIKE '%$search%'";
        $sql .= " OR description LIKE '%$search%'";
        $sql .= " OR price LIKE '%$search%'";
        $sql .= " ORDER by id DESC";
        $sql .= " LIMIT {$per_page}";
        $sql .= " OFFSET {$pagination->offset()}";
        $photos = Product::find_by_sql($sql);
        $tcount = count($photos);
        }
?>
<?php include_layout_template('header2.php'); ?>
   <div class="container">
   <P class="lead error-msg">There are <?php echo $tcount; ?> results out of <?php echo " " . $total_count; ?></P>
    <div class="row">
<div id="pagination" style="clear: both;">
<nav aria-label="Page navigation example">
  <ul class="pagination">  
    <?php 
    for($i=1; $i <= $pagination->total_pages(); $i++){
        if($i == $page) {
            echo "<li class='page-item'><a class='page-link'> <span class=\"selected\">{$i}</span></a></li> ";
        } else{
        echo " <li class='page-item'><a class='page-link' href=\"search.php?page={$i}\">{$i}</a></li> ";
    }
    }
    if($pagination->total_pages() > 1) {
        if($pagination->has_previous_page()) {
            echo "<li class='page-item'><a class='page-link' href=\"search.php?page=";
            echo $pagination->previous_page();
            echo "\">&laquo; Previous</a></li> ";
        }

        if($pagination->has_next_page()){
            echo "<li class='page-item'><a class='page-link' href=\"search.php?page=";
            echo $pagination->next_page();
            echo "\">Next &raquo;</a></li>";
        }
    }
    ?>
</ul>
    </nav>
</div>
</div>
</div>
     <div class="container">
    <div class="row">
        <?php foreach ($photos as $photo): ?>
      <div class="col-md-4 col-sm-6">
      <div class="thumbnail">
     <form method="post" action="cart.php?action=add&id=<?php echo $photo->id; ?>" role="form" class="form-vertical">
     <a href="order_review.php?id=<?php echo $photo->id; ?>"><img src="<?php echo $photo->image_path(); 
     ?>" class="img-thumbnail" alt="responsive image"></a>
    <div class="caption">
    <h3 class="text-info text-center"><?php echo $photo->title; ?></h3>
    <p class="text-muted text-center price card-header"><span class="currency">N</span><?php echo $photo->price; ?></p>
    <p class="text-center"><em><?php echo $photo->description; ?></em></p>
    <input type="hidden" name="id" class="form-control" value="<?php echo $photo->id; ?>" />
    <input type="hidden" name="title" class="form-control" value="<?php echo $photo->title; ?>" />
    <input type="hidden" name="slug" class="form-control" value="<?php echo $photo->slug; ?>" />
    <input type="hidden" name="description" class="form-control" value="<?php echo $photo->description; ?>" />
    <input type="hidden" name="price" class="form-control" value="<?php echo $photo->price; ?>"/>
    <div class="col-sm-4 mx-auto d-block">
    <select name="quantity" class="form-control" name="quantity">
        <option value="1">1</option>
        <option value="2">2</option>
        <option value="3">3</option>
        <option value="4">4</option>
        <option value="5">5</option>
    </select>
    </div>
      </div>
      <div class="col-sm-4 col-sm-push-3 mx-auto d-block">
      <input type="submit" name="add_to_cart" class="btn bg-success" value="Add to cart" />
      </div><br/>
      </form>
    </div>
     </div>
    <?php endforeach; 
    ?>
    </div>
</div>
<?php include_layout_template('footer2.php'); ?>

Try to call session_start(); at the beginn of any php code. If this doesnt work create new page to test, if any sessions are working. Maybe the configuration is not correct.

<?php
session_start();
$_SESSION['foo'] = "test";
var_dump($_SESSION);
<?php

        //var_dump($_POST);
        //var_dump($_SESSION);

        if(isset($_POST['submit']) || isset($_SESSION['search'])){
        // 1. the current page number ($current_page)
        $page = !empty($_GET['page']) ? (int)$_GET['page'] : 1;
        // 2. records per page ($per_page)
        $per_page = 2;
        // 3. total record count ($total_count)
        if(isset($_POST['submit'])) {
            $_SESSION['search'] = $_POST['search'];
            $searchvalue = $_POST['search'];
        } else {
            isset($_SESSION['search']);
            $searchvalue = $_SESSION['search'];
        }  
        $search = $database->escape_value($searchvalue);

        $sql  = "SELECT COUNT(*) FROM products WHERE image LIKE '%$search%'";
        $sql .= " OR title LIKE '%$search%'";
        $sql .= " OR slug LIKE '%$search%'";
        $sql .= " OR description LIKE '%$search%'";
        $sql .= " OR price LIKE '%$search%'";
        $sql = $database->query($sql);
        $sql = $database->fetch_array($sql);
        $total_count = array_shift($sql);

        // Find all photos
        // use pagination instead
        $pagination = new Pagination($page, $per_page, $total_count);
        // Instead of finding all records, just find the records

        $sql  = "SELECT * FROM products WHERE image LIKE '%$search%'";
        $sql .= " OR title LIKE '%$search%'";
        $sql .= " OR slug LIKE '%$search%'";
        $sql .= " OR description LIKE '%$search%'";
        $sql .= " OR price LIKE '%$search%'";
        $sql .= " ORDER by id DESC";
        $sql .= " LIMIT {$per_page}";
        $sql .= " OFFSET {$pagination->offset()}";
        $photos = Product::find_by_sql($sql);
        $tcount = count($photos);
        }

       // var_dump($_SESSION);
?>