public function joinCondition()
    {
        if (!isset($this->_joinCondition)) {
            $this->_joinCondition = Factory::filter($this);
        }
        return $this->_joinCondition;
    }
public function joinCondition()
    {
        if (!isset($this->_joinCondition)) {
            $this->_joinCondition = Factory::filter($this);
        }
        return $this->_joinCondition;
    }
public function joinCondition ( ) { if ( ! isset ( $ this -> _joinCondition ) ) { $ this -> _joinCondition = Factory :: filter ( $ this ) ; } return $ this -> _joinCondition ; }
The filter used for the ON clause of a JOIN
@return Filter
The filter used for the ON clause of a JOIN