how to set cakephp 3 email unique validation - validation

Question

I created a table users with 2 fields id(primary),(email)
I want email unique validation used following code but not working only not empty working.
<?php
namespace App\Controller;
use App\Model\Validation\UserValidator;
class UsersController extends AppController
{
public function register()
{
$this->loadModel("users");
if ($this->request->is('post')) {
$validator = new UserValidator();
$errors = $validator->errors($this->request->getData());
if (empty($errors)) {
} else {
$this->set('errors', $errors);
}
}
}
}
src/Model/Validation/UserValidator.php
<?php
namespace App\Model\Validation;
use Cake\Validation\Validator;
use Cake\ORM\Table;
use Cake\ORM\Rule\IsUnique;
class UserValidator extends Validator {
public function __construct()
{
parent::__construct();
$this
->notEmpty('name', 'The name field cannot be left empty')
->notEmpty('email', 'Fill Valid Email Id')
->add('email',['unique' => ['rule' => 'validateUnique', 'provider' => 'table', 'message' => 'Not unique']])
->notEmpty('mobile', 'Fill Valid 10 Digit Mobile No.');
}
}

Answer 1

create this file under \src\Model\Table\Userstable.php
updated
change the the filename capitalize the to make it \src\Model\Table\UsersTable.php
in my code below I validated my username and email as unique
use App\Model\Entity\User;
use Cake\ORM\Query;
use Cake\ORM\RulesChecker;
use Cake\ORM\Table;
use Cake\Validation\Validator;
use Cake\ORM\Rule\IsUnique;
/**
* Users Model
*
*/
class UsersTable extends Table
{
/**
* Initialize method
*
* #param array $config The configuration for the Table.
* #return void
*/
public function initialize(array $config)
{
parent::initialize($config);
$this->table('users');
}
/**
* Default validation rules.
*
* #param \Cake\Validation\Validator $validator Validator instance.
* #return \Cake\Validation\Validator
*/
public function validationDefault(Validator $validator)
{
$validator
->requirePresence('username','create')
->notBlank('username', 'A username is required')
->add('username', 'unique', [
'rule' => 'validateUnique',
'provider' => 'table',
'message' => 'Username is already used'
]);
$validator
->requirePresence('email','create')
->notBlank('email', 'An email is required')
->add('email', 'unique', [
'rule' => 'validateUnique',
'provider' => 'table',
'message' => 'Email is already used'
]);
return $validator;
}
public function buildRules(RulesChecker $rules)
{
$rules->add($rules->isUnique(['username']));
$rules->add($rules->isUnique(['email']));
return $rules;
}
}