mysqli_num_rows()期望参数1为mysqli_result，使用mysqli为布尔值 [英] mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean with mysqli

问题描述

我无法收到警告 sql查询正在工作，并且mysqli_query()返回1，并且每次我的数据库也被更新时.有什么问题吗?

I am not able to get the warning the sql query is working and mysqli_query() returns 1 and each time my database is also being updated . What is the problem?

警告:mysqli_num_rows()期望参数1为mysqli_result，第55行的C:\ xampp \ htdocs \ qq \ index.php中给出的布尔值

Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given in C:\xampp\htdocs\qq\index.php on line 55

的代码是

<?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"];

此代码中有错误:

$tval=$_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_rows其显示错误，

even if i am removing mysqli_num_rows its showing error on

推荐答案

根据另一个问题 INSERT命令将返回一个布尔值(true/false)，因此必须使用select命令来获得所需的结果

The INSERT command will return a boolean(true/false), So you must use select command to get the required result

这篇关于mysqli_num_rows()期望参数1为mysqli_result，使用mysqli为布尔值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！