ok, Thanks!now all is correct!!It seem a bit complicated, this isn't the standard php languages..
So is possible connect SilverStripe to my SQL database?To do this I need write query as explain in the guide..following silverstripe language?

SilverStripe has a templating engine which is different from just straight PHP. It wraps things in class's like ArrayData to make using the templates much more straight forward, and to keep using PHP syntax and options in the HTML.

For doing SQL you can use various methods here - http://doc.silverstripe.com/doku.php?id=sqlquery but as it says there a better way to do it sometimes is to use the tools the framework provides eg using DataObject::get() calls which are translated into SQL it just adds a wrapper to what you would normally write