sql 递归函数，根据父级ID获取所有子级(含自己)

------------------------------------
--用途：根据商家ID获取所有子商家(含自己商家)
--说明：
--时间：2011/5/6 12:44:42
--作者：李海生@Bool为1时包括自己商家信息0时不包括
--例子：select * from GetChildParent(17,1)
------------------------------------
ALTER FUNCTION [dbo].[GetChildParent]
(
@ID VARCHAR(10) ,
@bool INT
)
RETURNS @t TABLE
(
ID VARCHAR(10) ,
ParentID VARCHAR(10) ,
OrgName NVARCHAR(50) ,
Level INT
)
AS
BEGIN
DECLARE @counts INT
SELECT @counts = ISNULL(COUNT(*), 0)
FROM dbo.Customers_Business
WHERE Bid = @ID
IF ( @counts > 0 )
BEGIN

DECLARE @OrgName NVARCHAR(1000)
SELECT @OrgName = CONVERT(NVARCHAR(1000), Name) + '('
+ CONVERT(NVARCHAR(1000), Bid) + ')'
FROM Customers_Business
WHERE Bid = @ID
DECLARE @i INT
SET @i = 1
IF ( @bool > 0 )
BEGIN
INSERT INTO @t
SELECT @ID ,
@ID ,
@OrgName ,
0 --当前级，本级，如果不要的话可以注释掉或再加个参数来选择操作
INSERT INTO @t
SELECT Bid ,
ParentId ,
CONVERT(NVARCHAR(1000), Name) + '('
+ CONVERT(NVARCHAR(1000), Bid) + ')' ,
@i
FROM dbo.Customers_Business
WHERE ParentId = @ID
END
ELSE
BEGIN
INSERT INTO @t
SELECT Bid ,
ParentId ,
CONVERT(NVARCHAR(1000), Name) + '('
+ CONVERT(NVARCHAR(1000), Bid) + ')' ,
@i
FROM dbo.Customers_Business
WHERE ParentId = @ID
END

WHILE @@rowcount <> 0
BEGIN
SET @i = @i + 1
INSERT INTO @t
SELECT a.Bid ,
a.ParentId ,
a.Name ,
@i
FROM dbo.Customers_Business a ,
@t b
WHERE a.ParentId = b.ID
AND b.Level = @i - 1
END
END
RETURN
END