他为什么不给我看数据库里的结果？我用mysqli。

<h1>PC's</h1>
<form id="formPcs" method="POST">
  <input type="name" placeholder="Circutor_xxx">
  <input type="submit" value="Buscar" name="namehost">
</form>
<?php
  $connect = mysqli_connect("localhost","root","","circutor");

  if (@isset($_POST['namehost'])) {

    $viewquery = mysqli_query($connect, "SELECT * FROM hosts WHERE hostname='$_POST[namehost]'");
    if (mysqli_num_rows($viewquery) > 0) {
      while ($listar = mysqli_fetch_array($viewquery)) {
        ?>
          <h3><?php echo $listar['hostname']; ?></h3>
        <?php
      }
    }else{

      echo "NO HAY RESULTADOS EN LA BBDD";
    }

  }else{
    $viewquery = mysqli_query($connect, "SELECT * FROM hosts ORDER BY id ASC");
    while ($listar = mysqli_fetch_array($viewquery)) {
      ?>
        <h3><?php echo $listar['hostname']; ?></h3>
      <?php
    }
  }

 ?>

埃斯特档案馆ú斯奎达，你根本不知道é salta Directamte al else，坦比é很可能我在工作，必要的。