mysqli_num_rows()要求参数1为mysqli_result,布尔值为mysqli

我不能得到警告 SQL查询正在运行,mysqli_query()返回1,每次更新数据库时都会返回1。有什么问题?

警告:mysqli_num_rows()要求参数1为mysqli_结果,在第55行的c:\xampp\htdocs\qq\index.php中给出了布尔值。

代码的

<?php
 try{
  $host="localhost";

 $user="deb";
 $password="12345";
 $database="1";
 $conn=mysqli_connect($host,$user,$password,$database);
 if (mysqli_connect_errno())
 {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
 }
 echo "connected succesfully";
   }catch(Exception $e){
 echo $e->getMessage();
 }
 $select=mysqli_select_db($conn,$database);
 if($select)
  {
  echo "yipee";
  }

echo "<table>
<thead>
<tr>
    <th>Id</th>
    <th>Value</th>
    <th>Threshold Value</th>
    <th>Chances of Fire</th>
</tr>
</thead>";
$val=$_GET["val"];

此代码中存在错误:

$tval=$_GET["tval"];
 if ($val<$tval) {
 $res="less ";
 }
else{$res="exreme ";}
$sql1="INSERT INTO sensor (val,tval,result) VALUES 
('".$val."','".$tval."','".$res."')"; 
 $que=mysqli_query($conn,$sql1);
 if($que)
  {
  if(mysqli_num_rows($que))
   {
    while ($data=mysqli_fetch_array($que))
     {
    echo "<tr>";
    echo "<td>".$data['id']."</td><td>".$data['val']."/td> 
       <td>".$data['tval']."</td><td>".$data['result']."</td>";
    echo"</tr>";
     }
   }

   else{
      echo "nooooooo";
        } 
      }     
      echo"</table>"
        ? >

即使我正在删除mysqli_num_行,它在上显示错误