This is my Db table structuer.

I create ArticleRow class by extending Zend_Db_Table_Row_Abstract for get section and category names instead of section_id and category_id ,And user names instead of author_id and modified_by from Article Zend_Db_Table class.
I add "protected $_rowClass = 'ArticleRow';" to Article class and for init() method of ArticleRow(Zend_Db_Table_Row) I add
$articleTb= new Article();
$articleRow=$articleTb->select();
$articleRow->from( 'article');
$articleRow->join('section','section_id=section.id',array('section_name'=>'section.title'));
$articleRow->join('category','category_id=category.id',array('category_name'=>'category.title'));
$articleRow->join('user','author_id=user.id',array('author_name'=>'user.name'));
But I don't know how to get a the data of a specific row by passing id value from a controller.Please help me.Thank you.