sql server 子找父和父找子

父找子

with
RTD1 as(
select Id,pid from Sys_XCode
),
RTD2 as(
select * from RTD1 where id=1
union all
select RTD1.* from RTD2 inner join RTD1
on RTD2.id=RTD1.PID
)
select * from RTD2

子找父

with   

    RTU1 as(  

        select id ,pid from UserGroup  

    ),  

    RTU2 as(  

        select * from RTU1 where id=26  

        union all  

        select RTU1.* from RTU2 inner join RTU1   

        --on myT2.id=myT.PID  

        on RTU2.PID=RTU1.ID  

    )   

select * from RTU2