Sql Server CTE递归

WITH cte AS (
SELECT a.FNUMBER,a.FMATERIALID AS MainId,b.FMATERIALID AS ChileID,CAST(b.FMATERIALID AS VARCHAR(max)) AS lev FROM t_eng_bom a
JOIN dbo.T_ENG_BOMCHILD b ON a.fid =b.FID
WHERE a.fid = '100150'
UNION ALL
SELECT d.FNUMBER,d.MainId,d.ChileID,CAST(lev AS VARCHAR(max))+ CAST(d.ChileID AS VARCHAR(max)) AS lev FROM cte c
JOIN ( SELECT aa.FNUMBER,aa.FMATERIALID AS MainId,bbb.FMATERIALID AS ChileID FROM t_eng_bom aa
JOIN dbo.T_ENG_BOMCHILD bbb ON aa.fid =bbb.FID )d ON c.ChileID = d.MainId
)
SELECT * FROM cte ORDER BY lev

WITH cte as(

select a,b,c from tablea

union all

select a,b,c from cte a

join tablea b on a.a = b.b

)

select * from cte

语法：

[WITH[,n]]
　　::=
　　expression_name[(column_name[,n])]
　　AS(
　　CTE_query_definition1　--　定位点成员（也就是初始值或第一个结果集）
　　unionall
　　CTE_query_definition2　--　递归成员
　　)

最后传送门：http://blog.csdn.net/bin_520_yan/article/details/5998349#reply