left join (outer join) עם שדות לא משותפים

השאילתה :

SELECT PART.PARTNAME,RTOA (REALQUANT (SUM
(WARHSBAL.BALANCE)),2) AS EPARTDES,PART.PARTDES
FROM PART, PARTDES, PARTSTATS, WARHSBAL?, WAREHOUSES?, CUSTOMERS ?
WHERE (PART.PARTNAME LIKE '%' OR PART.PARTDES LIKE '%'
OR PARTDES.EPARTDES LIKE '%')
AND PART.PART = PARTDES.PART
AND PART.WTYPE <> 'Y'
AND PART.PARTSTAT = PARTSTATS.PARTSTAT
AND PARTSTATS.SELLFLAG = 'Y'
AND PART.PART=WARHSBAL.PART AND (WARHSBAL.ACT = 0 OR WARHSBAL.ACT < -1000)
AND WARHSBAL.WARHS = WAREHOUSES.WARHS AND WAREHOUSES.SELLFLAG = 'Y'
AND WARHSBAL.CUST = CUSTOMERS.CUST AND((CUSTOMERS.STATUSFLAG = 'Y' AND CUSTOMERS.SELLFLAG = 'Y') OR CUSTOMERS.STATUSFLAG <> 'Y')
GROUP BY 1,3
ORDER BY 1 FORMAT;