如何使層表平

Question

我有這樣的一個表：

Child | Parent 
AA |A 
A  |X 
B  |X 
X  |Y 
Y  |Z 

格言部門是知道的，但在每個分支的深度是未知

我希望它轉動到像這個：

Lv1 | Lv2 | Lv3 |lv4 | lv5 
Z |Y |X |B |Null 
Z |Y |X |A |AA 

有人可以幫忙，如果能提供SQL加一些說明，非常感謝！

Answer 1

我發現我的這個鏈接答案：https://www.sqlservercentral.com/Forums/Topic1071035-392-1.aspx

這裏是我改變代碼：

with cteTree 
as 
(

    Select CID,PID, 
      CNAME as LV1, 
      cast(Null as nvarchar(100)) as LV2, 
      cast(Null as nvarchar(100)) as LV3, 
      cast(Null as nvarchar(100)) as LV4, 
      cast(Null as nvarchar(100)) as LV5, 
      cast(Null as nvarchar(100)) as LV6, 
      cast(Null as nvarchar(100)) as LV7, 
      cast(Null as nvarchar(100)) as LV8, 
      cast(Null as nvarchar(100)) as LV9, 
      cast(Null as nvarchar(100)) as LV10, 
      cast(Null as nvarchar(100)) as LV11, 

      0 as Level 
    from PSFT_DEPT_TREE 
    where PID = 0 
    union all 
    Select Child.CID, 
      Child.PID, 
      LV1, 
      case when Level+1 = 1 then CNAME else LV2 end, 
      case when Level+1 = 2 then CNAME else LV3 end, 
      case when Level+1 = 3 then CNAME else LV4 end, 
      case when Level+1 = 4 then CNAME else LV5 end, 
      case when Level+1 = 5 then CNAME else LV6 end, 
      case when Level+1 = 6 then CNAME else LV7 end, 
      case when Level+1 = 7 then CNAME else LV8 end, 
      case when Level+1 = 8 then CNAME else LV9 end, 
      case when Level+1 = 9 then CNAME else LV10 end, 
      case when Level+1 = 10 then CNAME else LV11 end, 

      Level+1 
    from CteTree 
    join PSFT_DEPT_TREE child 
     on child.PID = CteTree.CID 
) 

select * from cteTree