sql语句拾遗

update tx_ry ry1 set px=(select px from tx_ry where id in (pk1,pk2) and id<>ry1.id) where id in (pk1,pk2);

2.自关联查询
select * from xt_xtmk where 1=1 start with mc='附加信息管理' connect by prior id=fid   --向下查
union
select * from xt_xtmk where 1=1 start with mc='附加信息管理' connect by prior fid=id   --向上查