如何在Sql Server 2000中用一条语句实现树的查询

以公司的网站栏目表为例，表结构（表名：Subject）如下：

 

字段名称	字段类型	字段长度
id	int	4
NAME	varchar	200
PARENTID	int	4
CODE	varchar	100

在数据库中创建一个自定义函数：

 

CREATE FUNCTION dbo.GetSubtreeInfo

( @manager_id AS char(5)

)

RETURNS @treeinfo table

( [id] [int] NOT NULL ,

[name] [varchar] (100) NOT NULL,

[parentid] [int] NOT NULL,

[code] [varchar] (100) NULL,

[levels] [int] NOT NULL

) AS

BEGIN

DECLARE @level AS int

SELECT @level = 0

INSERT INTO @treeinfo

SELECT [id], [name], [parentid], [code], @level

FROM [subject]

WHERE [id] = @manager_id

WHILE @@ROWCOUNT > 0

BEGIN

SET @level = @level + 1

INSERT INTO @treeinfo

SELECT E.[id], E.[name], E.[parentid], E.[code], @level

FROM [subject] AS E JOIN @treeinfo AS T

ON E.[parentid] = T.[id] AND T.[levels] = @level - 1

END

RETURN

END 

说明：其中的levels是树状结构的级数

使用方法：select SPACE(levels*3)+name ,* from GetSubtreeInfo(973) 其中973可以修改为你要开始查询的起始节点