Илья Белобородов

public function getAuthors(){
        return $this->hasMany(\app\models\Profile::className(), ['user_id'=>'id_author'])
            ->viaTable(\app\models\MaterialJoinAuthor::tableName(),['id_material' => 'id_material']);
}

$sql='UPDATE users SET last_update='.time().' where id_user='.Yii::app()->user->id;
Yii::app()->db->createCommand($sql)->execute();

$users=Users::model()->findAll([
    'condition'=>'t.last_update > :time',
    'params'=>[':time'=>time()-(60*60*15)], // 15 минут
]);

<?php 
     $arr=[
        'f1' => 'ssss',
        'f2' => 'sss2',
        'f' => [
            '11'=>'ww',
            'www'=>'wcec'
        ]
    ];

    echo json_encode($arr);

{"f1":"ssss","f2":"sss2","f":{"11":"ww","www":"wcec"}}

$arr=......// массив который нужно сортировать
$co=[];
      foreach($arr as $item){
        $co[]=$item['nomatch'];
      }
      array_multisort($co, SORT_ASC, $arr);