Дмитрий Ким

SELECT LEFT(`name`, 1) `abc`, `id`, `name` FROM `persons` ORDER BY `name` ASC;

$data = [
  ['abc' => 'а', 'id' => 1, 'name' => 'Абрамов Михаил Фёдорович'],
  ['abc' => 'а', 'id' => 2, 'name' => 'Агутин Юрий Николаевич'],
  ['abc' => 'б', 'id' => 4, 'name' => 'Баринов Олег Юрьевич'],
];

$alphabet = [];
foreach ($data as $row){
  $alphabet[$row['abc']][$row['id']] = $row['name'];
}

$alphabet = [
  'а' => [
    1 => 'Абрамов Михаил Фёдорович',
    2 => 'Агутин Юрий Николаевич',
  ],
  'б' => [
    4 => 'Баринов Олег Юрьевич',
  ],
];

foreach($alphabet as $alpha => $rows){
  echo '<h2>'.$alpha.'</h2>';
  echo '<ul>';
  foreach ($rows as $id => $name){
    echo '<li><a href="/person?id='.$id.'">'.$name.'</a></li>';
  }
  echo '</ul>';
}

class Order {
  const SECRET_KEY = 'not-log-secret-key-2213123123';
}

$token = Yii::$app->security->hashData($order->id, Order::SECRET_KEY);

Для подтверждения пройдите по <a href="http://site.domain/order/confirm?token=<?= $token ?>">ссылке</a>

class OrderController extends Controller {
  public function actionConfirm($token){
    if ($id = \Yii::$app->security->validateData($token, Order::SECRET_KEY)){
      if (($order = Order::findOne($id)) && $order->updateAttributes(['confirmed' => true])){
        Yii::$app->session->addFlash('success', 'Талон подтвержден');
        return $this->redirect('orders');
      }
    }

    throw new NotFoundHttpException();
  }
}

$items = Table::find()->where(['id' =>[1, 2, 3, 5]])->indexBy('id')->all();
$items = array_replace([2 => null, 3 => null, 1 => null, 5 => null], $items);

echo Select2::widget([
    'name' => 'my-select2',
    'data' => [1 => 'One', 2 => 'Two'],
    'options' => [
        'placeholder' => 'Select a number ...',
        'options' => [
            2 => ['disabled' => true],
        ]
    ],
]);

<select>
  <option value="1">One</option>
  <option value="2" disabled="disabled">Two</option>
</select>

[
  'label' => 'Роль',
  'value' => function($model){
    return $model->authAssignment->authItem->description;
  }
]

$query = User::find()->with([
  'authAssignment' => function($q){
    return $q->with('authItem');
  }
]);

var tags = [];
tags[1] = 'Авто';
tags[12] = 'Автомобили';
alert(tags.indexOf("Автомобили"));

public function getSubnet(){
    return $this->hasOne(Subnet::class, ['id' => 'subnet']);
}
public function getBras(){
    return $this->hasOne(Bras::class, ['id' => 'bras'])->via('subnet');
    // или
    // return $this->hasOne(Bras::class, ['id' => 'bras'])->viaTable(Subnet::tableName(), ['id' => 'subnet']);
}

ClientSearch {
  public $brasName; // добавляем атрибут в модель поиска
}

'id',
[
  'attribute' => 'brasName', // выводим в гриде
  'value' => function(Client $model){
    return $model->bras ? $model->bras->name : null;
  }
],

'defaultOrder' => [
  'processed' => SORT_ASC,
  'date' => SORT_ASC,
]