If you want to select from one table but also join with another.

Zend

$select= $this->_getTable()->select()->setIntegrityCheck(false)
	->from(array('BLG' => 'articles'), array('month' => new Zend_Db_Expr($m), 'count' => new Zend_Db_Expr('COUNT(BLG.id_articles)')))
	->joinLeft(
		array('LNG' => 'languages'),
		'LNG.id_languages = BLG.id_languages',
		array('lang' => 'code')
	)
	->where('LNG.code = ?', $lang)
;