public function getEquationQty()
    {
        $tbl = $this->_resource->getTableName(self::TBL_WRHS_QTY);
        $result = 'SUM(`' . $tbl . '`.`' . Quantity::A_TOTAL . '`)';
        return $result;
    }
public function getEquationQty()
    {
        $tbl = $this->_resource->getTableName(self::TBL_WRHS_QTY);
        $result = 'SUM(`' . $tbl . '`.`' . Quantity::A_TOTAL . '`)';
        return $result;
    }
public function getEquationQty ( ) { $ tbl = $ this -> _resource -> getTableName ( self :: TBL_WRHS_QTY ) ; $ result = 'SUM(`' . $ tbl . '`.`' . Quantity :: A_TOTAL . '`)' ; return $ result ; }
MOBI-397

@return string equation for qty summary.
MOBI - 397