php不能正常使用html

请检查with session是否为空或不类似

include ("db_conn.php");

function clean_input($data)
{
$data = stripslashes($data);
$data = trim($data);
$data = htmlspecialchars($data);
return $data;
}
//registration form data validation

if(!empty($_POST['Go']))
{
$email= $password= "";
$email= clean_input($_POST['email']);
$pass= clean_input($_POST['pass']);
$pass = hash("sha256", $pass);
$type= $_GET['type'];

global $query;

if($type=="student")
{
$query= "SELECT * FROM STUDENT WHERE email='$email' AND password='$pass'";
}

elseif($type=="company")
{
$query= "SELECT * FROM COMPANY WHERE email='$email' AND password='$pass'";
}
echo $query;
$query1= mysqli_query($dbhandle,$query);
if(!$query1)
{
echo 'MySQL Error: ' . mysqli_error();
        exit;
        }

$count= mysqli_num_rows($query1);

if($count==0)
{echo "No Data";
}
else
{
while($row=mysqli_fetch_assoc($query1))
if($type=="student")
{

session_start();
$_SESSION['sname']= $row['F_Name'].' '.$row['L_Name'];
$_SESSION['s_id']= $row['id'];
header('Location: /Internshala/index.php?s_id='.$_SESSION['s_id']);

}
elseif($type=="company")
{
session_start();
$_SESSION['cname']=$row['Name'];
echo $_SESSION['cname'];
$_SESSION['c_id']=$row['c_id'];
header('Location: /Internshala/index.php?c_id='.$_SESSION['c_id']);
}
}
}

最后试试这个

如果使用OR运算符，则即使其中一个会话变量未设置，脚本也将显示除其他块之外的所有内容

---

即使在使用And运算符后，当编码提示if（条件）错误时，它也不会工作。但是，在与Fred ii讨论时，我注意到结尾处

之间的不匹配，这最终让我发现此处缺少一个“，

您的注销脚本是什么样子的？@ohgod为什么它包含一个简单的会话\u destroy（），现在会话\u destroy（）之后是否有任何数据打印到脚本中；@Ohgodwhy不，只需简单重定向到index.phpC可以尝试会话重新生成ID吗？仍然不起作用，我想if语句中会有一个二进制乘法，即&。为什么下次，您可以在这次更新您的答案。：）
include ("db_conn.php");

function clean_input($data)
{
$data = stripslashes($data);
$data = trim($data);
$data = htmlspecialchars($data);
return $data;
}
//registration form data validation

if(!empty($_POST['Go']))
{
$email= $password= "";
$email= clean_input($_POST['email']);
$pass= clean_input($_POST['pass']);
$pass = hash("sha256", $pass);
$type= $_GET['type'];

global $query;

if($type=="student")
{
$query= "SELECT * FROM STUDENT WHERE email='$email' AND password='$pass'";
}

elseif($type=="company")
{
$query= "SELECT * FROM COMPANY WHERE email='$email' AND password='$pass'";
}
echo $query;
$query1= mysqli_query($dbhandle,$query);
if(!$query1)
{
echo 'MySQL Error: ' . mysqli_error();
        exit;
        }

$count= mysqli_num_rows($query1);

if($count==0)
{echo "No Data";
}
else
{
while($row=mysqli_fetch_assoc($query1))
if($type=="student")
{

session_start();
$_SESSION['sname']= $row['F_Name'].' '.$row['L_Name'];
$_SESSION['s_id']= $row['id'];
header('Location: /Internshala/index.php?s_id='.$_SESSION['s_id']);

}
elseif($type=="company")
{
session_start();
$_SESSION['cname']=$row['Name'];
echo $_SESSION['cname'];
$_SESSION['c_id']=$row['c_id'];
header('Location: /Internshala/index.php?c_id='.$_SESSION['c_id']);
}
}
}

 if(empty($_SESSION['c_id']) || !isset($_SESSION['c_id']))
 {
   //after not login
 } 
 else
 {
   //after login
 }

if(!empty($_SESSION['c_id']) || !empty($_SESSION['c_id']))
{
     //Login here
} 
else
{
    //Please Login
 }

if( !isset($_SESSION['c_id']) || !isset($_SESSION['s_id']) )
  {
    //after not login
  }
  else {

         //after login
  }