Php 获取错误警告：mysqli:：query（）：无法'；t在我的代码中获取mysqli

获取错误警告：mysqli:：query（）：无法在中获取mysqli

  <?php

    include 'includes/config.php';
    include 'includes/database.php';
    ini_set('display_errors', 1);
    ini_set('display_startup_errors', 1);
    error_reporting(E_ALL);



    if (isset($_POST['sign'])) {
      $name=$_POST['email'];
      $pass=$_POST['password'];
      $query_two="SELECT * FROM admin WHERE user='$name' AND password='$pass' ";
      $runn=$db->query($query_two);

      $row_login=$runn->fetch_assoc();

    if ($row_login['user']==$name && $row_login['password']==$pass) {
      session_start();

      $_SESSION["username"] = $name;
      header('Location: adminpane.php');
      exit();

    }

    else {
      echo "<script>
    check();

      </script>

      ";
      exit();


    }


    }


     ?>

将某物用作：

<?php 
session_start();
include 'includes/config.php';
include 'includes/database.php';
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

if (isset($_POST['sign'])) {
  $name = mysqli_real_escape_string($db,$_POST['email']);
  $pass = mysqli_real_escape_string($db,$_POST['password']);
  $query_two = "SELECT * FROM admin WHERE user='$name' AND password='$pass'";
  $runn = mysqli_query($db,$query_two);
  $row_login = mysqli_fetch_assoc($runn);

  if ($row_login['user']==$name && $row_login['password']==$pass) {
   $_SESSION["username"] = $name;
   header('Location: adminpane.php');
   exit();
  } else {
   echo "<script>check();</script>";
   exit();
 }
}
?>

没有一个调用
mysqli:：query（）
，因此至少缺少一些相关代码。顺便说一句，你很容易受到SQL注入的攻击…我已经添加了代码，请再次检查！！既然您已经发布了数据库连接详细信息（用户名、密码），请立即更改它们。否则，您的数据库中很快就会有一些访问者。
 <?php

define('DB_HOST', 'xxx.xxx.xxx.xxx');
define('DB_USERNAME', 'XXX');
define('DB_PASSWORD', 'XXX');
define('DB_NAME', 'myDB');


 ?>

<?php 
session_start();
include 'includes/config.php';
include 'includes/database.php';
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

if (isset($_POST['sign'])) {
  $name = mysqli_real_escape_string($db,$_POST['email']);
  $pass = mysqli_real_escape_string($db,$_POST['password']);
  $query_two = "SELECT * FROM admin WHERE user='$name' AND password='$pass'";
  $runn = mysqli_query($db,$query_two);
  $row_login = mysqli_fetch_assoc($runn);

  if ($row_login['user']==$name && $row_login['password']==$pass) {
   $_SESSION["username"] = $name;
   header('Location: adminpane.php');
   exit();
  } else {
   echo "<script>check();</script>";
   exit();
 }
}
?>