/**
* @param \yii\db\Query $select
* @param \yii\db\Connection $db
* @return string
*/
function getsql(\yii\db\Query $select, $db = null)
{
if ($db === null) {
$db = Yii::$app->getDb();
}
return $select->prepare(Yii::$app->db->queryBuilder)->createCommand($db)->rawSql;
}