I trying to check if a username is already in use in my db but it's not echoing anything (blank page when i run ) , i want to get a true or false response
<?php
mysql_connect("localhost", "root", "") or die(mysql_error());
mysql_select_db("data1") or die(mysql_error());
$usercheck = "john";
$sanitizeduser= filter_var($usercheck, FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_LOW);
$check = mysql_query("SELECT EXISTS(SELECT 1 FROM users WHERE username = $sanitizeduser)");
echo $check;
?>