Question

我的父母表看起来像这样

CHILD_ID | PARENT_ID | NAME
1        | Null      | Bill
2        | 1         | Jane
3        | 1         | Steve
4        | 2         | Ben
5        | 3         | Andrew

我想获得像这样的结果集

Bill
---Jane
------Ben
---Steve
------Andrew

我知道我需要做一个排名查询来排名水平和自我加入，但我能在网上找到的只是CTE递归

我之前已在Oracle中完成此操作，但未在MS SQL中完成此操作

Answer 1

有点hacky，可以改进，但希望它显示原则......

;with relation (childId, parentId, childName, [level], [orderSequence])  
as  
(  
select childId, parentId, childName, 0, cast(childId as varchar(20))  
from @parents  
where parentId is null  
union all  
select p.childId, p.parentId, r.[level]+1, cast(r.orderSequence + '_' + cast(p.childId as varchar) as varchar(20))  
from @parents p  
inner join relation r on p.parentId = r.childId  
)  

select right('----------', ([level]*3)) +childName  
from relation  
order by orderSequence

如果您想避免递归，那么另一种方法是使用相关的树结构信息实现树表 - 请参阅http://www.sqlteam.com/article/more-trees-hierarchies-in-sql了解

Answer 2

declare @pc table(CHILD_ID int, PARENT_ID int, [NAME] varchar(80));
 
insert into @pc
select 1,NULL,'Bill' union all
select 2,1,'Jane' union all
select 3,1,'Steve' union all
select 4,2,'Ben' union all
select 5,3,'Andrew' union all
select 6,NULL,'Tom' union all
select 7,8,'Dick' union all
select 8,6,'Harry' union all
select 9,3,'Stu' union all
select 10,7,'Joe';
 
 
; with r as (
      select CHILD_ID, PARENT_ID, [NAME], depth=0, sort=cast(CHILD_ID as varchar(max))
      from @pc
      where PARENT_ID is null
      union all
      select pc.CHILD_ID, pc.PARENT_ID, pc.[NAME], depth=r.depth+1, sort=r.sort+cast(pc.CHILD_ID as varchar(30))
      from r
      inner join @pc pc on r.CHILD_ID=pc.PARENT_ID
      where r.depth<32767
)
select tree=replicate('-',r.depth*3)+r.[NAME]
from r
order by sort
option(maxrecursion 32767);

这是一个艰难的:)。我将示例扩展为包括＆gt; 1棵树。结果到目前为止看起来不错。

Answer 3

WITH DirectReports (ParentUniqId, UniqId, SortID)
AS
(
    SELECT e.ParentUniqId, e.UniqId, e.UniqId as SortID
    FROM Coding.Coding AS e
    WHERE isnull(ParentUniqId ,0)=0
    UNION ALL
    SELECT e.ParentUniqId, e.UniqId,, d.SortID * 100 + e.UniqId  as SortID
    FROM Coding.Coding AS e
    INNER JOIN DirectReports AS d
        ON e.ParentUniqId = d.UniqId

)
SELECT ParentUniqId, Perfix,SortID
FROM DirectReports order by rtrim(SortID) , uniqid

父/子层次结构树视图

3 个答案: