1、效率最快的

MERGE INTO user_member_info a
USING ( select min(UP.created) as cre,min(up.shop_no) as shop_no,up.memberid as memberid 
       from user_platform_relation up,
       ( select memberid as mid,min(created) as cre 
            from user_platform_relation 
            group by memberid) um
      where up.created = um.cre and up.memberid = um.mid
      group by up.memberid) b
ON (a.id = b.memberid
    )
WHEN MATCHED THEN UPDATE SET a.created = b.cre,a.shop_no = b.shop_no,a.modified_time = sysdate

where  a.shop_no is null;

2、效率其次

update (select ui.userid as uiuid,oi.user_id as oiuid,
               ui.id as uimid,oi.memberid as oimid,
               oi.modified_time as oitime
      from user_member_info ui, reserveorder_info oi
      where ui.brandid = oi.brandid and ui.mobile = oi.telphone)

      set oiuid = uiuid, oimid = uimid;

3、效率最差

UPDATE RETURN_FACTORYORDER r SET (r.XSBILLDATE,r.DQ) = (
  SELECT f.saletime,f.bezei FROM RF f WHERE r.BILL = f.BILL
)