Question

我正在尝试从数据库中删除一行。当我执行PHP脚本时，出现错误消息：

Notice: Trying to get property 'num_rows' of non-object in /home/send.php on line 46。

有人知道我的脚本出了什么问题吗？

第46行= if ($result10->num_rows > 0) {

这是我用来删除行的PHP脚本：

$link10 = mysqli_connect("localhost", "root", "password", "database");

if($link10 === false){
die("ERROR: Could not connect. " . mysqli_connect_error());
}

$sql10 = "DELETE FROM statement WHERE id = '". $_SESSION['id'] ."' AND number = '". $_GET['number'] ."'";
$res10 = mysqli_query($link10, $sql10) ;

$result10 = $link10->query($sql10);

if ($result10->num_rows > 0) {
//script

}

Answer 1

您已经在这里执行查询：

$res10 = mysqli_query($link10, $sql10);

因此您可以使用以下命令访问num_rows：

if(mysqli_num_rows($res10) > 0)

并删除此行：

$result10 = $link10->query($sql10);

完整代码：

$link10 = mysqli_connect("localhost", "root", "password", "database");

if($link10 === false) {
    die("ERROR: Could not connect. " . mysqli_connect_error());
}

$sql10 = "DELETE FROM statement WHERE id = '". $_SESSION['id'] ."' AND number = '". $_GET['number'] ."'";
$res10 = mysqli_query($link10, $sql10);

if(mysqli_num_rows($res10) > 0) {
//script
}

Answer 2

这就是你要做的

if ($res10->num_rows > 0) {
//script

}

请在下面尝试。我已经注释了不需要的代码

$link10 = mysqli_connect("localhost", "root", "password", "database");

if($link10 === false){
die("ERROR: Could not connect. " . mysqli_connect_error());
}

$sql10 = "DELETE FROM statement WHERE id = '". $_SESSION['id'] ."' AND number = '". $_GET['number'] ."'";
$res10 = mysqli_query($link10, $sql10) ;

//$result10 = $link10->query($sql10);

if ($res10->num_rows > 0) {
//script

}

更新部分

<?php
   $dbhost = 'localhost';
   $dbuser = 'root';
   $dbpass = 'password';
   $dbname = 'database';
   $conn = mysqli_connect($dbhost, $dbuser, $dbpass,$dbname);

   if(! $conn ) {
      die('Could not connect: ' . mysqli_error());
   }
   echo 'Connected successfully<br>';

$sql = "DELETE FROM statement WHERE id = '". $_SESSION['id'] ."' AND number = '". $_GET['number'] ."'";
   $result = mysqli_query($conn, $sql);

   if (mysqli_num_rows($result) > 0) {
     echo "deleted successfully";
   } else {
      echo " results cannot be deleted";
   }
   mysqli_close($conn);
?>

Answer 3

错误消息表示 $ result10 不是对象，因此您不能将其用作对象

尝试一下：

$link10 = mysqli_connect("localhost", "root", "password", "database");
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

$sql10 = "DELETE FROM statement WHERE id = '". $_SESSION['id'] ."' AND number = '". $_GET['number'] ."'";
mysqli_query($link10, $sql10) ;

if (mysqli_affected_rows($link10) > 0) {
  //script
}

以下是W3C

上的类似示例

属性“ num_rows”是非对象？

3 个答案: