$students_query = $this->db->select()
->from($this->_name, '')
->setIntegrityCheck(false)
->join('<ANOTHER_TABLE_NAME>', "<ANOTHER_TABLE_NAME>.uid = {$this->_name}.teacher_id", array('uid', 'ulogin'))
->where("{$this->_name}.course_id = ?", $course_id)
->order("<ANOTHER_TABLE_NAME>.ulogin");