public function query($columns = "*"){
    $this->db->select($columns)
             ->from($this->getSource());
             
    return $this;
  }
public function query($columns = "*"){
    $this->db->select($columns)
             ->from($this->getSource());
             
    return $this;
  }
public function query ( $ columns = "*" ) { $ this -> db -> select ( $ columns ) -> from ( $ this -> getSource ( ) ) ; return $ this ; }
Build a select-query

@Param   String    $columns   Columns to select
@Return  Object    $this
Build a select - query