Question

我在SQL Server 2008中使用T / SQL

我有一个包含以下列的表MyTable：

 CHILD
 PARENT
 HIERARCHY

HIERARCHY列目前是空的，但我想填充它。

我有一些代码可以创建一个层次结构ID（改编自Recursive Child/Parent queries in T/SQL中的代码）这段代码效果非常好。

with n(CHILD, PARENT, GENERATION, hierarchy) as (
select CHILD, PARENT,0, CAST(CHILD as nvarchar) as GENERATION from MyTable
where PARENT=1 
union all
select nplus1.CHILD, nplus1.PARENT, GENERATION+1, 
cast(n.hierarchy + '/' + CAST(nplus1.CHILD as nvarchar) as  nvarchar)
 from 
MyTable nplus1 inner join n on nplus1.PARENT=n.CHILD and    
)

我可以通过以下方式查看此查询的结果：

select CHILD,GENERATION,Hierarchy from n

但是我想将结果放回MyTable中的Hierarchy列中。这段代码不起作用！

update MyTable e
set HIERARCHY='/'+(select hierarchy from n where n.CHILD=e.CHILD)

有谁知道怎么做？谢谢！

Answer 1

也许是这样的：

;with n(CHILD, PARENT, GENERATION, hierarchy) as (
select CHILD, PARENT,0, CAST(CHILD as nvarchar) as GENERATION from MyTable
where PARENT=1 
union all
select nplus1.CHILD, nplus1.PARENT, GENERATION+1, 
cast(n.hierarchy + '/' + CAST(nplus1.CHILD as nvarchar) as  nvarchar)
 from 
MyTable nplus1 inner join n on nplus1.PARENT=n.CHILD and    
)
UPDATE MyTable 
   SET Hierarchy=n.hierarchy
FROM MyTable 
JOIN n
  ON n.CHILD=MyTable.CHILD

修改

你的意思是这样的：

;with n(CHILD, PARENT, GENERATION, hierarchy) as ( select CHILD, PARENT,0, CAST(CHILD as nvarchar) as GENERATION from MyTable where PARENT=1 union all select nplus1.CHILD, nplus1.PARENT, GENERATION+1, cast(n.hierarchy + '/' + CAST(nplus1.CHILD as nvarchar) as nvarchar) from MyTable nplus1 inner join n on nplus1.PARENT=n.CHILD and ) UPDATE MyTable SET Hierarchy='/'+n.hierarchy+'/' FROM MyTable e JOIN n ON n.child=e.child

将递归T / SQL查询的结果存储在表中

1 个答案: