Hierarchyid 常用操作

---------内置函数------------

select hierarchyid::GetRoot()--0x

select hierarchyid::Parse('/1/1/') --0x5AC0

select cast(0x5AC0 as hierarchyid)--0x5AC0

select cast('/1/' as hierarchyid)--0x5AC0

select cast(0x5AC0 as hierarchyid).ToString()--/1/1/

select cast(0x5AC0 as hierarchyid).GetLevel()--2

-----------IsDescendantOf------------ 判断@Node是否为@parent的子节点

declare @Node hierarchyid

declare @parent hierarchyid

set @Node='/1/2/3/4/'

set @parent='/1/2/'

select @Node.IsDescendantOf(@parent)--1

select @parent.IsDescendantOf(@Node)--0

--------GetAncestor ( n ) ----------返回指定层次的祖先.

declare @hy hierarchyid

declare @c int

set @hy='/1/1/2/1/'

set @c=@hy.GetLevel()

select @hy.GetAncestor(0).ToString()--/1/1/2/1/

select @hy.GetAncestor(1).ToString()--/1/1/2/

select @hy.GetAncestor(@c).ToString()--/

select @hy.GetAncestor(@c+1).ToString()--null

-----------GetDescendant-----------返回子集

//1.如果父级为NULL，则返回NULL。

---如果父级不为NULL----

--2.而child1 和child2 为NULL，则返回父级的子级。--

declare @hy hierarchyid

set @hy='/1/1/'

select @hy.GetDescendant(NULL,NULL).ToString()--/1/1/1/

--3. 返回值 在child1于child2之间 , child1>child2 且必须为@hy的子集--

select @hy.GetDescendant('/1/1/5/',null).ToString()--/1/1/6/

select @hy.GetDescendant(null,'/1/1/5/').ToString()--/1/1/4/

select @hy.GetDescendant('/1/1/2/','/1/1/5/').ToString()--/1/1/3/

select @hy.GetDescendant('/1/1/3/','/1/1/4/').ToString()--/1/1/3.1/

select @hy.GetDescendant(null,'/1/1/1/5/').ToString()--报异常

select @hy.GetDescendant('/1/1/5/','/1/1/3/').ToString()--报异常

---------◆GetReparentedValue ：可以用来移动节点 --------------

注意：@parent是Node的祖先

declare @Node hierarchyid

DECLARE @NodeChild1 hierarchyid

declare @parent hierarchyid, @new hierarchyid

set @Node='/1/2/3/4/'

set @NodeChild1='/1/2/3/4/5/'

set @parent='/1/2/'

set @new='/5/6/7/'

SET @Node=@Node.GetReparentedValue(@parent, @new)

select @Node.ToString()--/5/6/7/3/4/

SELECT @NodeChild1.GetReparentedValue(hierarchyid::Parse('/1/2/3/4/'), @Node).ToString()

移动子树

另一项常用操作是移动子树。下面的过程采用 @oldMgr 的子树作为参数，使其（包括 @oldMgr）成为 @newMgr 的子树。

CREATE PROCEDURE MoveOrg(@oldMgr nvarchar(256), @newMgr nvarchar(256) )

AS

BEGIN

DECLARE @nold hierarchyid, @nnew hierarchyid

SELECT @nold = OrgNode FROM HumanResources.EmployeeDemo WHERE LoginID = @oldMgr ;

SET TRANSACTION ISOLATION LEVEL SERIALIZABLE

BEGIN TRANSACTION

SELECT @nnew = OrgNode FROM HumanResources.EmployeeDemo WHERE LoginID = @newMgr ;

SELECT @nnew = @nnew.GetDescendant(max(OrgNode), NULL)

FROM HumanResources.EmployeeDemo WHERE OrgNode.GetAncestor(1)=@nnew ;

UPDATE HumanResources.EmployeeDemo

SET OrgNode = OrgNode.GetReparentedValue(@nold, @nnew)

WHERE OrgNode.IsDescendantOf(@nold) = 1 ;

COMMIT TRANSACTION

END ;

GO

参考：

http://technet.microsoft.com/zh-cn/library/bb677212(v=sql.105).aspx

http://blog.csdn.net/tjvictor/article/details/4395681

http://msdn.microsoft.com/zh-cn/library/bb677290(v=sql.105).aspx

http://entityframework.codeplex.com/discussions/415185

http://stackoverflow.com/questions/25195890/need-examples-for-entityframework-hierarchyid

http://blog.csdn.net/tonyzhou2008/article/details/5100683

http://www.tuicool.com/articles/iEnum2f

http://blog.csdn.net/szstephenzhou/article/details/8277667

http://blog.csdn.net/ldslove/article/details/5628007