登录错误并登录优化[重复]

Question

This question already has an answer here:

• Warning: mysqli_select_db() expects parameter 1 to be mysqli, null given 6 answers

Hey guys I have been working on a social networking site and have been working on the login and registration systems. I am pretty new to php so my code may not be the best. The issue I am having right now is my login. This is my log in form on my index.php page.

<form name="loginform" method="post" action="includes/login.php" >
  <table>

  <input type="submit" id="submitbox" name="login" value="Submit">

  <input type="password" name="password" id="passwordbox" required="true" placeholder="Password">

  <input type="text" name="username" id="usernamebox" required="true" placeholder="Username">

  </table>

</form>

I send the form to my login.php page (includes folder) and process the information and if successful start the session and redirect the user to the home.php page. When I click submit to log me in I am brought to an error saying:

Warning: mysqli_query() expects parameter 1 to be mysqli, resource given in /Applications/XAMPP/xamppfiles/htdocs/VolleypagesFixed/includes/login.php on line 14

Warning: mysqli_error() expects parameter 1 to be mysqli, resource given in /Applications/XAMPP/xamppfiles/htdocs/VolleypagesFixed/includes/login.php on line 14

This line is on my log in page and this is the code for that page:

<?php
// start the session
session_start();

require_once ('connect.php');

// if form is submitted

if(isset($_POST['username']) and isset($_POST['password'])) {
$username = $_POST['username'];
$password = $_POST['password'];

$query = "SELECT * FROM `users` WHERE username='$username' and password='$password'";

line 14 - $result = mysqli_query($con, $query) or die(mysqli_error($con));
$count = mysqli_num_rows($result);

// create session if values are equal
if($count == 1) {
    // cookie is set
   if(isset($_COOKIE['ID'])) {
            $id = mysql_real_escape_string($_COOKIE['ID']);
        }
        if(!isset($id)){
            die("Cookie not found");
        }
} else {
    echo "Invalid Login";
    header("Location: http://localhost/FolderName/index.php");
}
}

// if user is logged in redirect
if(isset($_COOKIE['ID'])) {
header("Location: http://localhost/FolderName/home.php");
}

?>

Any help on the error on line 14 or any advice and how I have set my login up would be very helpful!

</div>

Answer 1

Try this

Use

 mysqli_connect('localhost', 'root', 'root', 'test');

Instead:

  mysql_connect