id    name    parent
 1     aaa
 2     bbb         1
 3     ccc         1
 4     ddd         2
 5     eee         2
 6     fff         5

id_1  id_2  id_3   id_n+1    id    name
null  null  null     ...      1     aaa
   1  null  null     ...      2     bbb
   1  null  null     ...      3     ccc
   1     2  null     ...      4     ddd
   1     2  null     ...      5     eee
   1     2     5     ...      6     fff