或多或少都做過樹狀目錄、產品分類之類的二級或三級菜單，如果遇到更多級的分類，就一般使用遞歸了。在程序中使用遞歸或多或少會增加一些性能上的開銷。
之前我用ASP.Net在程序中實現過非遞歸的無限級分類目錄，但考慮到移植性不強，就改成了存儲過程，發出來大家共同研究一下，到目前為止，測試過程中還沒發現問題，另外，代碼方面沒經過什麼優化。
通常情況下，我們更多的操作是讀取目錄，所以，在下面的實現中，讀取我們只需要一Select語句就夠了,不使用遞歸，理論上無限級~！
===================================================
表結構：
表名：Tb_Column
表結構（所有字段非空）：
Column_ID int 主鍵（注：非標識）
Column_Name nvarchar(50)分類名稱
Parent_ID int 父分類ID（默認值0）
Column_Path nvarchar(1000) 分類路徑
Column_Depth int分類深度(默認值0）
Column_Order int排序(默認值0)
Column_Intro nvarchar(1000)分類說明
================================================
存儲過程一：新建分類
CREATE PROCEDURE sp_Column_Insert
(
@Parent_ID int,
@Column_Name nvarchar(50),
@Column_Intro nvarchar(1000)
)
AS
Declare @Err As int
Set @Err=0
Begin Tran
--通過現有記錄獲取欄目ID
Declare @Column_ID As int
Declare @Column_Depth As int
Select @Column_ID = Max(Column_ID) From Tb_Column
IF @Column_ID Is Not Null
Set @Column_ID = @Column_ID+1
Else
Set @Column_ID = 1
--判斷是否是頂級欄目，設置其Column_Path和Column_Order
Declare @Column_Path As nvarchar(1000)
Declare @Column_Order As int
IF @Parent_ID = 0
Begin
Set @Column_Path =Ltrim(Str(@Column_ID))
Select @Column_Order = Max(Column_Order) From Tb_Column
IF @Column_Order Is Not Null
Set @Column_Order = @Column_Order + 1
Else --如果沒有查詢到記錄，說明這是第一條記錄
Set @Column_Order = 1
--深度
Set @Column_Depth = 1
End
Else
Begin
--獲取父節點的路徑和深度
Select @Column_Path = Column_Path ,@Column_Depth = Column_Depth From Tb_Column Where
Column_ID=@Parent_ID
IF @Column_Path Is Null
Begin
Set @Err = 1
Goto theEnd
End
--獲取同父節點下的最大序號
Select @Column_Order = Max(Column_Order) From Tb_PicColumn Where Column_Path like
''''+@Column_Path+''|%'' Or Column_ID = @Parent_ID
IF @Column_Order Is Not Null --如果序號存在，那麼將該序號後的所有序號都加1
Begin
--更新當前要插入節點後所有節點的序號
Update Tb
_Column Set Column_Order = Column_Order +1 Where Column_Order
>@Column_Order
--同父節點下的最大序號加上1，構成自己的序號
Set @Column_Order = @Column_Order + 1
End
Else
Begin
Set @Err=1
Goto theEnd
End
--父節點的路徑加上自己的ID號，構成自己的路徑
Set @Column_Path = @Column_Path + ''|'' + Ltrim(Str(@Column_ID))
--深度
Set @Column_Depth = @Column_Depth+1
End
Insert Into Tb_Column(Column_ID,Column_Name,Parent_ID,Column_Path,Column_Depth,Column_Order,Column_Intro)
Values(@Column_ID,@Column_Name,@Parent_ID,@Column_Path,@Column_Depth,@Column_Order,@Column_Intro)
IF @@Error<>0
Begin
Set @Err=1
Goto theEnd
End
--更新當前記錄之後的記錄的ORDER
--Update Tb_Column Set Column_Order = Column_Order+1 Where Column_Order > @Column_Order
theEnd:
IF @Err=0
Begin
Commit Tran
Return @Column_ID
End
Else
Begin
Rollback Tran
Return 0
End
GO
===================================================
存儲過程二：刪除分類
CREATE PROCEDURE sp_Column_Delete
(
@Column_ID int
)
AS
Declare @Err As int
Set @Err = 0
Begin Tran
--首先查詢該節點下是否有子節點
Select Column_ID From Tb_Column Where Parent_ID = @Column_ID
IF @@RowCount<>0
Begin
Set @Err = 1
Goto theEnd
End
--獲取該節點的Column_Order,為了刪除後整理其他記錄的順序
Declare @Column_Order As int
Select @Column_Order = Column_Order From Tb_Column Where Column_ID = @Column_ID
IF @Column_Order Is NUll
Begin
Set @Err =2
Goto theEnd
End
--更新其他記錄的Column_Order
Update Tb_Column Set Column_Order = Column_Order -1 Where Column_Order >@Column_Order
IF @@Error<>0
Begin
Set @Err =3
Goto theEnd
End
--刪除操作
Delete From Tb_Column Where Column_ID=@Column_ID
IF @@Error<>0
Begin
Set @Err =4
Goto theEnd
End
--更新其他記錄的Column_ID
--Update Tb_Column Set Column_ID= Column_ID - 1 Where Column_ID >@Column_ID
--IF @@Error<>0
-- Begin
-- Set @Err =5
-- Goto theEnd
-- End
theEnd:
IF @Err = 0
Begin
Commit Tran
Return 0 --刪除成功
End
Else
Begin
IF @Err=1
Begin
Rollback Tran
Return 1 --有子節點
End
Else
Begin
Rollback Tran
Return 2--未知錯誤
End
End
GO
=============================================
存儲過程三：編輯分類
CREATE PROCEDURE sp_Column_Update
(
@Column_ID int,
@Parent_ID int
@Column_Name nvarchar(50),
@Column_Intro nvarchar(1000)
)
AS
Declare @Err As int
Set @Err=0
Begin Tran
--獲取修改前的：Parent_ID,Column_Depth,Column_Order
Declare @oParent_ID As int
Declare @oColumn_Depth As int
Declare @oColumn_Order As int
Declare @oColumn_Path As nvarchar(1000)
Select @oParent_ID = Parent_ID, @oColumn_Depth = Column_Depth,@oColumn_Order = Column_Order, @oColumn_Path = Column_Path From Tb_Column Where Column_ID = @Column_ID
IF @oParent_ID Is Null
Begin
Set @Err = 1
Goto theEnd
End
--如果父ID沒有改變，則直接修改欄目名和欄目簡介
IF @oParent_ID = @Parent_ID
Begin
Update Tb_Column Set Column_Name = @Column_Name,Column_Intro = @Column_Intro Where Column_ID = @Column_ID
IF @@Error <> 0
Set @Err = 2
Goto theEnd
End
Declare @nColumn_Path As nvarchar(1000)
Declare @nColumn_Depth As int
Declare @nColumn_Order As int
--獲取當前節點作為父節點所包含的節點數[包括自身] 注：如果返回 “1” 說明是單節點
Declare @theCount As int
Select @theCount = Count(Column_ID) From Tb_Column Where Column_ID=@Column_ID Or Column_Path like ''''+@oColumn_Path+''|%''
IF @theCount Is Null
Begin
Set @Err = 3
Goto theEnd
End
IF @Parent_ID=0 --如果是設置為頂級節點，將節點設置為最後一個頂級節點
Begin
--Print ''設置為頂級欄目''
Set @nColumn_Path = Ltrim(Str(@Column_ID))
Set @nColumn_Depth =1
Select @nColumn_Order = Max(Column_Order) From Tb_Column
IF @nColumn_Order Is NULL
Begin
Set @Err = 4
Goto theEnd
End
Set @nColumn_Order = @nColumn_Order - @theCount + 1
--更新三部分 1 節點本身 2 所有子節點 2 本樹更改之前的後面記錄的順序
--Print ''更新本欄目之前位置後面的所有欄目[不包括本欄目下的子欄目]的：Column_Order''
Update Tb_Column Set Column_Order = Column_Order-@theCount Where (Column_Order >@oColumn_Order) And (Column_Path Not like ''''+@oColumn_Path+''|%'')
IF @@Error <> 0
Begin
Set @Err = 7
Goto theEnd
End
--Print ''更新本欄目的：Parent_ID,Column_Path,Column_Depth,Column_Order,Column_Name,Column_Intro''
Print ''Order : ''+Ltrim(Str(@nColumn_Order))
Update Tb_Column Set Parent_ID=@Parent_ID,Column_Path = @nColumn_Path,Column_Depth = @nColumn_Depth,Column_Order = @nColumn_Order, Column_Name = @Column_Name,Column_Intro = @Column_Intro Where Column_ID = @Column_ID
IF @@Error <> 0
Begin
Set @Err = 5
Goto theEnd
End
--Print ''更新本欄目下的所有子欄目的：Column_Path,Column_Depth,Column_Order''
Update Tb_Column Set Column_Path = Replace(Column_Path,@oColumn_Path,@nColumn_Path),Column_Depth = Column_Depth + (@nColumn_Depth-@oColumn_Depth),Column_Order = Column_Order+( @nColumn_Order-@oColumn_Order) Where Column_Path like ''''+@oColumn_Path+''|%''
IF @@Error <> 0
Begin
Set @Err = 6
Goto theEnd
End
End
Else
Begin
--獲取未來父節點的相關信息,並設置本節點的相關值
Select @nColumn_Depth = Column_Depth,@nColumn_Path = Column_Path From Tb_Column Where Column_ID = @Parent_ID
IF @nColumn_Depth Is NULL Or @nColumn_Path Is Null
Begin
Set @Err = 8
Goto theEnd
End
Set @nColumn_Depth = @nColumn_Depth +1
Select @nColumn_Order =Max(Column_Order) From Tb_Column Where Column_ID = @Paren
t_ID Or Column_Path like ''''+@nColumn_Path+''|%''
IF @nColumn_Order Is NULL
Begin
Set @Err = 9
Goto theEnd
End
Set @nColumn_Path = @nColumn_Path +''|''+ Ltrim(Str(@Column_ID))
IF @nColumn_Order = @oColumn_Order+1 --如果新的父節點是原來位置上端最近一個兄弟,則所有節點的順序都不改變
Begin
Update Tb_Column Set Parent_ID=@Parent_ID,Column_Path = @nColumn_Path,Column_Depth = @nColumn_Depth, Column_Name = @Column_Name,Column_Intro = @Column_Intro Where Column_ID = @Column_ID
IF @@Error <> 0
Begin
Set @Err = 10
Goto theEnd
End
End
Set @nColumn_Order = @nColumn_Order + 1
--更新三部分 1 本樹更改之前的後面（或前面）記錄的順序 1 節點本身 3 所有子節點
--分為向上移或象下移
--Print ''更新本欄目之前位置後面的所有欄目[或者本欄目之後位置] [不包括本欄目下的子欄目]的：Column_Order''
IF @nColumn_Order < @oColumn_Order
Begin
Update Tb_Column Set Column_Order = Column_Order+@theCount Where Column_Order<@oColumn_Order And Column_Order >=@nColumn_Order And (Column_Path Not like ''''+@oColumn_Path+''|%'') And Column_ID<>@Column_ID
IF @@Error <> 0
Begin
Set @Err = 12
Goto theEnd
End
End
Else
Begin
Update Tb_Column Set Column_Order = Column_Order-@theCount Where Column_Order >@oColumn_Order And Column_Order<@nColumn_Order And (Column_Path Not like ''''+@oColumn_Path+''|%'') And Column_ID<>@Column_ID
IF @@Error <> 0
Begin
Set @Err = 13
Goto theEnd
End
End
--Print ''更新本欄目的：Parent_ID,Column_Path,Column_Depth,Column_Order,Column_Name,Column_Intro''
Print ''Order : ''+Ltrim(Str(@nColumn_Order))
IF @nColumn_Order > @oColumn_Order
Set @nColumn_Order = @nColumn_Order - @theCount
Update Tb_Column Set Parent_ID=@Parent_ID,Column_Path = @nColumn_Path,Column_Depth = @nColumn_Depth,Column_Order = @nColumn_Order, Column_Name = @Column_Name,Column_Intro = @Column_Intro Where Column_ID = @Column_ID
IF @@Error <> 0
Begin
Set @Err = 10
Goto theEnd
End
--Print ''更新本欄目下的所有子欄目的：Column_Paht,Column_Depth,Column_Order''
Update Tb_Column Set Column_Path = Replace(Column_Path,@oColumn_Path,@nColumn_Path),Column_Depth = Column_Depth + (@nColumn_Depth-@oColumn_Depth),Column_Order = Column_Order+(@nColumn_Order-@oColumn_Order) Where Column_Path like ''''+@oColumn_Path+''|%''
IF @@Error <> 0
Begin
Set @Err = 11
Goto theEnd
End
End
theEnd:
IF @Err<>0 --如果有錯誤則返回錯誤號
Begin
Rollback Tran
Return @Err
End
Else --如果沒有錯誤就返回0
Begin
Commit Tran
Return 0
End
GO
=========================================
存儲過程四：顯示分類（只是一條select語句）
分類列表：
CREATE PROCEDURE sp_Column_List
AS
SELECT Column_ID, Column_Name, Parent_ID, Column_Path, Column_Depth,
Column_Order, Column_Intro
FROM Tb_Column
ORDER BY Column_Order
GO
=======================================
