in oracle it's not the correct way to fetch it :-) select .. from (select .. from ta left join tb on ta.bid = tb.bid ) TBB left join tc on tbb.cid = tc.cid
oracle 中要这样写:SELECT TA.AID, NVL(TB.BD,'NULL'), NVL(TC.CD,'NULL') FROM TA,TB,TC WHERE TA.BID = TB.BID (+) AND nvl(TB.CID,9999) = TC.CID(+)
select ..
from (select ..
from ta left join tb on ta.bid = tb.bid ) TBB left join tc on tbb.cid = tc.cid
FROM TA,TB,TC
WHERE TA.BID = TB.BID (+)
AND nvl(TB.CID,9999) = TC.CID(+)