Empty results on LEFT JOIN in Codeigniter - php

Question

So I'm trying to find users from my database that don't have ANY rows in another table for the previous month, although it looks like my query is correct; I'm getting empty results?
public function __construct() {
parent::__construct();
//Set Payment Dates
$this->dates = array('1st', '8th', '15th', '25th');
//Which Month do the figures need submitting as
$this->monthPrev = date('F Y', strtotime(date('F Y')." -1 month"));
$this->currentMonth = date('F Y', strtotime('this month'));
}
public function getUnreportedQuarterlies()
{
$this->db->select('quarterly_figures.month, quarterly_figures.centre, users.name, users.email');
$this->db->from('quarterly_figures');
$this->db->join('users', 'users.name = quarterly_figures.centre', 'left');
$this->db->where("quarterly_figures.month", $this->monthPrev);
$this->db->where("quarterly_figures.centre IS NULL");
return $this->db->get()->result();
}
My database rows look something like so:
users
CREATE TABLE `users` (
`id` int(11) NOT NULL,
`name` varchar(45) DEFAULT NULL,
`email` varchar(45) DEFAULT NULL,
`password` varchar(45) DEFAULT NULL,
`address` varchar(45) DEFAULT NULL,
`owners_password` varchar(45) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1;
INSERT INTO `users` (`id`, `name`, `email`, `password`, `address`, `owners_password`) VALUES
(1, 'Aldridge', 'aldridge#website.co.uk', 'password', '127.0.0.1', 'password');
quarterly_figures
CREATE TABLE `quarterly_figures` (
`id` int(11) NOT NULL,
`centre` varchar(45) DEFAULT NULL,
`month` varchar(45) DEFAULT NULL,
`date` date DEFAULT NULL,
`direct_debits` varchar(45) DEFAULT NULL,
`money_paid` varchar(45) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1;
INSERT INTO `quarterly_figures` (`id`, `centre`, `month`, `date`, `direct_debits`, `money_paid`) VALUES
(1, 'Rugby', 'January 2019', '2019-01-01', '128', '3519.00');

Answer 1

The 'user' table has no relation with the 'quarterly_figures' table , If there is no relation returned data is not possible. you can insert an users.id into 'quarterly_figures' for each input.