用户登录（使用会话）的麻烦

Question

I'm trying to make a log in system for users to login on my site. For some reason I can't seem to get my code to identify that a user exists, it always thinks the user doesn't exist in my database even when it does. I was hoping someone could look over my code and tell me if something is wrong, as I can't find any errors.

Also I should mention I'm very well aware none of this code is safe or secure, I would like to leave it that way for now.

Here is my table information:

<!--  Login form -->
        <div id="userLogin">
            <form name="user_login" id="Login" method="post" action="loginSF.php">

                Username : <input type="text" name="yourUsername" id="username" ><br /> 
                <span id="usernameWarnings" style="color:black"> </span> <br />  

                Password : <input type="password" name="yourPassword" id="userPassword" > <br />
                <span id="passwordWarnings" style="color:black"> </span> <br />

                <input type="submit" value="login" onclick="return validateLoginForm()" >
            </form>
        </div>

Here is my PHP code for loginSF.php: (updated with SQL fix) (Problem still EXISTS)

<?php 

session_start(); // starts session

require_once 'databaseLogin.php'; //login info
$db_server = mysqli_connect($db_hostname, $db_username, $db_password, $db_database); //connection

if(mysqli_connect_errno($db_server))
{
    echo "failed to connect to mySQL: " . mysqli_connect_error();
}
//$loggedIn = mysqli_query($db_server,"SELECT User_Name FROM members");

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

$query = "SELECT `User_Name`, `Password` FROM `members` WHERE User_Name='$username' AND Password='$password'";
$loggedIn = mysqli_query($db_server, $query);

// check username and password match
if(mysqli_num_rows($loggedIn) == 1)
{
    echo "Login Successful";
}
else
{
    echo "Login failed";
}

?>

users in database:

User_Name Password

Tester345 tttttt

Answer 1

Your code is vulnerable. I assume it's just a learning project

change

$query = "SELECT 'User_Name', 'Password' FROM `members` WHERE User_Name='$username' AND Password='$password'";

to

$query = "SELECT `User_Name`, `Password` FROM `members` WHERE User_Name='$username' AND Password='$password'";