递归树查询

--表结构
CREATE TABLE [dbo].[PSY_Web_MenuClass](
 [ModuleCode] [varchar](32) NOT NULL,
 [ModuleName] [varchar](128) NOT NULL,
 [ShortModuleName] [varchar](64) NULL,
 [LevelID] [int] NOT NULL,
 [ParentCode] [varchar](32) NULL
 CONSTRAINT [PK_PSY_WEB_MENUCLASS] PRIMARY KEY NONCLUSTERED 
(
 [ModuleCode] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]


/* ModuleCode 根节点，ParentCode 父节点*/

CREATE FUNCTION f_MenuSort(@ModuleCode varchar(32)=NULL,@sort int=1)
RETURNS @t_Level TABLE(ModuleCode varchar(32),sort int)
AS
BEGIN
 DECLARE cod_cur CURSOR LOCAL
 FOR
 SELECT ModuleCode FROM PSY_Web_MenuClass
 WHERE ParentCode=@ModuleCode OR (@ModuleCode IS NULL AND ParentCode IS NULL)
 OPEN cod_cur
 FETCH cod_cur INTO @ModuleCode
 WHILE @@FETCH_STATUS=0
 BEGIN
  INSERT @t_Level VALUES(@ModuleCode,@sort)
  SET @sort=@sort+1
  IF @@NESTLEVEL<32 --如果递归(嵌套查询)层数未超过32层(递归(嵌套查询)最大允许32层)
  BEGIN
  --开始递归查找当前节点的子节点
   INSERT @t_Level SELECT * FROM f_MenuSort(@ModuleCode,@sort)
   SET @sort=@sort+@@ROWCOUNT  --排序号加上子节点个数
  END
  FETCH cod_cur INTO @ModuleCode
 END
 RETURN
END
GO

SELECT a.*
FROM PSY_Web_MenuClass a,f_MenuSort('MYSUN',2) b
WHERE a.ModuleCode=b.ModuleCode


--------------------------------------------------2
CREATE FUNCTION f_LPad
( 
@i int,@len int 
) 
RETURNS nvarchar(max) 
AS 
BEGIN 
RETURN cast (replicate('0', @len - len(@i) ) + convert(nvarchar,@i) as nvarchar(max)) 
END 

 

CREATE PROCEDURE PSYP_GetMenuTree
----单个父节点
@MenuCode varchar(32)=NULL 
AS 
BEGIN 
with ReplicateMenu 
as 
( 
select *,0 as Level,cast('0' as nvarchar(max)) as TreePath from PSY_Web_MenuClass where ModuleCode = @MenuCode 
union all 
select A.*,rm.Level + 1,rm.TreePath + dbo.f_LPad(Row_Number() over (order by A.ModuleCode desc),8) as TreePath from PSY_Web_MenuClass as A inner join ReplicateMenu as rm on A.ParentCode = rm.ModuleCode ) 
SELECT * from ReplicateMenu  
END

----单个父节点


Create PROCEDURE PSYP_GetMenuTree
---多父节点
@MenuCode varchar(32)=NULL 
AS 
BEGIN 
with ReplicateMenu 
as 
( 
select *,0 as Level,cast(Row_Number() over (order by A.ModuleCode desc) as nvarchar(max)) as TreePath from PSY_Web_MenuClass where ModuleCode = @MenuCode 
union all 
select csc.*,rm.Level + 1,rm.TreePath + dbo.Lpad(Row_Number() over (order by A.ModuleCode desc),8) as TreePath from  PSY_Web_MenuClass as A inner join ReplicateMenu as rm on A.ParentCode = rm.ModuleCode ) 
SELECT * from ReplicateMenu
END 
---多父节点


exec psyp_GetMenuTree 'MYSUN'