无法使用我的数据库注册

Question

I need to make a Sign in form for my website. And I have to use MySQLi because MySQL will cause decaprated on my try. So, here's the index.php code:

<?php
session_start();ob_start();

$con=mysqli_connect("localhost","root","","oos");
if (mysqli_connect_errno()) echo "Failed to connect to MySQL: " . mysqli_connect_error();

    if(isset($_POST['signin']))
    {
        $username = $_POST['userid'];
        $pass = $_POST['password'];

        $query1 = "select * from admintb where adID = '$username' and adPass = 'password' ";
        $result1 = mysqli_query($con,$query1) or die;

        $co=0;

        while($row=mysqli_fetch_assoc($result1)) $co++;
        if($co==1)
        {
            $_SESSION['a']=$username;
            header("Location: main_menu.php");
        }
    }   ?>

The problem is, when I make $username="admin" and $password = "admin", it will go to main_menu.php alright. But when I try to do as above, base on my database, it won't go to main_menu.php. How can I sign in, go to the main_menu.php using ID from my database?

Answer 1

Sorry, I already checked it, it's a stupid mistake. Inside this snippet:

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

    $query1 = "select * from admintb where adID = '$username' and adPass = 'password' ";
    $result1 = mysqli_query($con,$query1) or die;

fix to this:

$query1 = "select * from admintb where adID = '$username' and adPass = '$pass' ";