php - Why the code does not work?

Question

The issue is within the MySQL connect and query part (first part worked):

<?php
$param=$_GET['m'];
$param=str_replace("-", " ", $param);
$param=ucwords($param); 
echo $param; 
$host="localhost";
$username="user_name";
$password="password_here";
$database_name="database_name_here";
$link=mysqli_connect('host','username','password','database_name');
if (mysqli_connect_errno()) {
printf("Connect failed: %s
", mysqli_connect_error());
exit();
}
$query=$mysqli_query($link, "SELECT column_name FROM table_name WHERE another_column_name='$param'");
echo $query; 
mysqli_close($link);
?>

I get the following error:

"Connect failed: Unknown MySQL server host 'host' (20)"

...and the code is correct according to PhpCodeChecker.com.

Thanks.

Answer 1

This line

$link=mysqli_connect('host','username','password','database_name');

should be:

 $link=mysqli_connect($host,$username$,$password,$database_name);