Hi Stackoverflow Community, I'm pretty new so yea, this is my first question and post.
I try right now to do a more or less login page on my php site, its not much of a deal with a database. i get this error when i want to visit my site -f /var/log/apache2/error.log
"Error: Call to undefined function mysqli_connect() in /var/www/html/upload.php:7\nStack trace:\n#0 {main}\n thrown in /var/www/html/upload.php on line 7"
PHP Version: PHP 7.2.24-0ubuntu0.18.04.2 (cli) (built: Jan 13 2020 18:39:59) ( NTS )
Full Code (from the PHP part):
<?php
$host="localhost";
$user="root";
$password="";
$db="demo";
$a=mysqli_connect('localhost','root','','demo');
mysqli_select_db($a,$db);
if(isset($_POST['username'])){
$uname=$_POST['username'];
$password=$_POST['password'];
$sql="select * from demo where User='".$uname."'AND Pass='".$password."' limit 1";
$result=mysqli_query($a, $sql);
if(mysqli_num_rows($result)!==0){
echo " You Have Successfully Logged in";
exit();
}
else{
echo " You Have Entered Incorrect Password";
exit();
}}
?>