view.php

<?php
    session_start();
    $host=$_SESSION['host'];
?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>
<header>
        <div class="head">
            <h1>
                MyLibrary
            </h1>
            <button class="but"><a href="<?php 
             if($host=="admin")
             {
                 ?> lib.php<?php ;
             }
             else{
                 ?>lab.php <?php ;
             }
            ?>">Back</a></button>
        </div>
    </header>
    <div class="box2">
        <table bordercolor="black">
            <tr bordercolor="black">
                <th>book num</th>
                <th>book name</th>
            </tr>
    <?php
             $mysql=new mysqli("localhost","root","","acharya") or die(mysqli_error($mysql));
             $result=$mysql->query("SELECT * FROM user") or die(mysqli_error($mysql));
                if($result-> num_rows> 0)
                {
                    while($row = $result->fetch_assoc())
                    {
                        echo "<tr><td>".$row["booknum"]."</td><td>".$row["bookname"]."</td></tr>";
                    }
                    echo "</table>";
                }
             ?>
    </div>
</body>
</html>