how do I set PDO attributes in db.php

In config/db.php I want to set default PDO scenarios as follows but when I do gii does not create models and yii is getting an exception. Any suggestions?

    'attributes' => [

        // Not setting DEFAULT


        // CASE_LOWER causes gii to not work and other Yii errors



in /home/devalp5/public_html/yii2basic/vendor/yiisoft/yii2/base/Component.php at line 143

throw new UnknownPropertyException('Getting unknown property: ’ . get_class($this) . ‘::’ . $name);

Also, gii creates an empty model with PDO::CASE_LOWER