PHP If / Else语句

I have a mysql table called users with the following fields:

username - password - role

The role consists of normal user and admin.

What I want is so when an admin logs in it gets redirected to another page and not the same page a normal user would log in. My code is as follows:

<?php
include("../includes/db.php");

$username=$_POST['username'];
$password=$_POST['password'];

$username = stripslashes($username);
$password = stripslashes($password);
$username = mysql_real_escape_string($username);
$password = mysql_real_escape_string($password);

$sql="SELECT * FROM Users WHERE username='$username' and password='$password' And role = 'normaluser'";
$result=mysql_query($sql);

$count=mysql_num_rows($result);

if($count==1){
session_register("username");
session_register("password");
header("location:myaccount.php");
}
?>

I have the code working for the normal user but I just don't know how to write the code for the admin part.

I'd say

$sql="SELECT role FROM Users WHERE username='$username' and password='$password'";
$result=mysql_query($sql);
while ($row = mysql_fetch_object($result)) {
    //one hit i hope?!
    //DONT save your apssword in the session!!!!
    //session_register("username");
    //session_register("password");

    $role = $row->role;

}
if($role == "user"){
    redirect1
}elseif($role == "admin"){
   redirect2;
}else{
  redirect panic
}

Retrieve role from the query, check to see what it is, then set the header location accordingly.

$sql = "SELECT * FROM Users WHERE username='$username' and password='$password'";
// ...
if($count == 1){
   $user = mysql_fetch_array($result);
   if ($user['role'] === 'normaluser')
   {
      session_register("username");
      session_register("password");
      header("location:myaccount.php");
   }
   if ($user['role'] === 'admin')
   {
      header("location:admin.php");
   }
}

define some constants like below or use the bitmasking algoritim. (php_manual).

index.php or if your using a framework check the docs.

define('USER_ADMIN', 'a');
define('USER_USER', 'u');

build a permissions table with type text set to null

`permissions` text null

to build your user_permissions row in your views use the checkbox's

<input type="checkbox" name="permissions[]" value="u" selected />
<input type="checkbox" name="permissions[]" value="a" selected />

assigning data

$user='';

$user = (isset($_SESSION['uid'])) ? User::find($_SESSION['uid']) : '';



if(isset($user) && in_array(USER_ADMIN, $user['permissions']))
{
   //i am an admin
}
else
{
  //i am NOT an admin
}