PHP Decode

<?php
if(isset($_GET['Id'])){
    $f_id = $_GET['Id'];
    $query = $pdo->prepare("select * from aptech where Id = :id");
    $query->bindParam('Id',$f_id);
    $query->execute();
    $result = $query->fetch(PDO::FETCH_ASSOC);
    // print_r($res);
}
?>

<div class="container mt-5">
    <form action="" method="post">
    <div class="form-group">
     <label for="">Name</label>
     <input type="text" name="name" value="<?php echo $result['name']?>" id="" class="form-control" placeholder=""
     aria-describedby="helpId">
    </div>

    <div class="form-group">
     <label for="">Email</label>
     <input type="text" name="email" value="<?php echo $result['email']?>" id="" class="form-control" placeholder=""
     aria-describedby="helpId">
    </div>

    <div class="form-group">
     <label for="">City</label>
     <input type="text" name="city" value="<?php echo $result['city']?>" id="" class="form-control" placeholder=""
     aria-describedby="helpId">
    </div>

    <div class="form-group">
     <label for="">Department</label>
     <input type="text" name="department" value="<?php echo $result['department']?>" id="" class="form-control" placeholder=""
     aria-describedby="helpId">
    </div>
    
    <div class="form-group">
     <label for="">Salary</label>
     <input type="text" name="salary" value="<?php echo $result['salary']?>" id="" class="form-control" placeholder=""
     aria-describedby="helpId">
    </div>

    <div class="form-group">
     <label for="">Subject</label>
    <select class="form-control" name="sub_id" id="">
     <option>Select Subject</option>
     <?php
    $query = $pdo->query("select * from content");
    $result = $query->fetchAll(PDO::FETCH_ASSOC);
    foreach($result as $sub){
     ?>
     <option value="<?php echo $sub['Sub_id']?>"><?php echo $sub['Sub_name']?></option>
    </div>
    <?php
    }
    ?>
</select>
</div>
<button type="submit" class="btn btn-info" name="update">Update</button>
    </form>
    </div>

    
    <?php
    if(isset($_POST['update'])){
        $name = $_POST['name'];
        $email = $_POST['email'];
        $city = $_POST['city'];
        $department = $_POST['department'];
        $salary = $_POST['salary'];
        $sub_id = $_POST['sub_id'];
        $query = $pdo->prepare("update employee set name = :name , email = :email , city = :city , department = :dept, salary = :salary ,
         subject_id = :sub_id where id = :id");

        $query->bindParam('name', $name);
        $query->bindParam('email', $email);
        $query->bindParam('city', $city);
        $query->bindParam('department', $department);
        $query->bindParam('salary', $salary);
        $query->bindParam('sub_id', $sub_id);
        $query->bindParam('id', $f_id); 
        $query->execute();
        echo "<script>alert('updated successfully')</script>";
    }
    ?>