级联删除

1，--   cascade,

2，with my1 as(select * from T_KM_Tree where kmid = @KMID
    union all select T_KM_Tree.* from my1, T_KM_Tree where my1.kmid = T_KM_Tree.parentid)
    delete from T_KM_Tree where exists (select kmid from my1 where my1.kmid = T_KM_Tree.kmid and my1.kmid!=@KMID);