I have attempted to make a login test using php but the data is not showing inside the database..What's the problem?Following are the lines of code for signup.
`
include 'databasehandler.php';
$first=$_POST['first'];
$last=$_POST['last'];
$uid=$_POST['uid'];
$password=$_POST['password'];
$sql="INSERT INTO profile(first, last, uid, password)
VALUES('$first, $last, $uid, $password')";
$result=mysqli_query($conn,$sql);
header("Location:main.php");`