--批量对符合条件的表记录进行更新--aa代表查询出的符合条件数据的别名--aa后的表示需要符合的条件--loop后开始写更新操作begin  for aa in (select a.objectid               from geographic_info a, geographic_info_bf b              where a.objectid = b.objectid                and b.pgeocode = 'xxx') loop    update geographic_info       set qxcode = 'xxx', pgeocode = 'xxx'     where objectid = aa.objectid;  end loop;end;