T-SQL无限级分解

我们在做分类处理的时候，总会遇到递归的处理，比如说地区就是一个例子，中国--北京--西城区，我们可以把这样的信息存储在一个数据表中，用ParentID区分根节点和叶子节点。

假如我们要做导航，得到了”西城区”，但是还要得到他的父级，或夫父级，一种方式是用程序来处理，也是很简单，另一种方式就是用数据库的功能。

既然数据库能完成这件事，何必在用程序呢？在SqlServer2005以前的版本中，也能处理这种情况，不过当时用的是存储过程，代码也比较多，表设计的时候，还的加一个表示“深度”的字段，当时我也写过相关的文章，参见：存储过程实现无限级分类（1）存储过程实现无限级分类（2）存储过程实现无限级分类（3）但是，在学习SqlServer2005新加的特性的时候，注意到WITH语句能实现这样的功能，并且代码简单，简练，最重要的是好理解。

下面是一张递归的表结构图：里边的parentID记录的就是他们之间的关系；比如我们要查询id = 10008,并且parentID 为10008的数据怎么办呢？如：呵呵，不留悬念了，直接上代码吧！其实挺容易理解的：WITH CategoryInfo AS(SELECT id,text,parentid FROM Recursive WHERE id=10008UNION ALLSELECT a.id,a.text,a.parentid FROM Recursive AS a,CategoryInfo AS b WHERE a.parentid= b.id)SELECT*FROM CategoryInfo看看是不是简单，简练，好理解！赶快试试吧！这是从上向下查，如果从下向上查，怎么查呢，自己举一反三吧！在做考题的的时候，涉及到分类，虽然不是无限级的，但是，为了以后扩展用，想做成无限级，在网上找找了，一个用存储过程作的，虽然添加，编辑，移动，用的是存储过程，可是在读出来的时候只用了一条Select 语句，感觉挺爽的，下面我把存储过程列出来，我只用到了添加，编辑，没有用到移动。

1，表结构============================================= ======表结构：表名：Tb_Column表结构（所有字段非空）：Column_ID int 主键（注：非标识）Column_Name nvarchar(50)分类名称Parent_ID int 父分类ID（默认值0）Column_Path nvarchar(1000) 分类路径Column_Depth int分类深度(默认值0）Column_Order int排序(默认值0)Column_Intro nvarchar(1000)分类说明============================================= ===2.添加的存储过程CREATE PROCEDURE sp_Column_Insert(@Parent_ID int,@Column_Name nvarchar(50),@Column_Intro nvarchar(1000))ASDeclare @Err As intSet @Err=0Begin Tran--通过现有记录获取栏目IDDeclare @Column_ID As intDeclare @Column_Depth As intSelect @Column_ID = Max(Column_ID) From Tb_ColumnIF @Column_ID Is Not NullSet @Column_ID = @Column_ID+1ElseSet @Column_ID = 1--判断是否是顶级栏目，设置其Column_Path和Column_OrderDeclare @Column_Path As nvarchar(1000)Declare @Column_Order As intIF @Parent_ID = 0BeginSet @Column_Path =Ltrim(Str(@Column_ID))Select @Column_Order = Max(Column_Order) From Tb_ColumnIF @Column_Order Is Not NullSet @Column_Order = @Column_Order + 1Else --如果没有查询到记录，说明这是第一条记录Set @Column_Order = 1--深度Set @Column_Depth = 1EndElseBegin--获取父节点的路径和深度Select @Column_Path = Column_Path ,@Column_Depth = Column_Depth From Tb_Colu mn WhereColumn_ID=@Parent_IDIF @Column_Path Is NullBeginSet @Err = 1Goto theEnd--获取同父节点下的最大序号Select @Column_Order = Max(Column_Order) From Tb_PicColumn Where Column_Path like''+@Column_Path+'|%'Or Column_ID = @Parent_IDIF @Column_Order Is Not Null --如果序号存在，那么将该序号后的所有序号都加1Begin--更新当前要插入节点后所有节点的序号Update Tb_Column Set Column_Order = Column_Order +1 Where Column_Order>@Column_Order--同父节点下的最大序号加上1，构成自己的序号Set @Column_Order = @Column_Order + 1EndElseBeginSet @Err=1Goto theEndEnd--父节点的路径加上自己的ID号，构成自己的路径Set @Column_Path = @Column_Path + '|' + Ltrim(Str(@Column_ID))Set @Column_Depth = @Column_Depth+1EndInsert Into Tb_Column(Column_Name,Parent_ID,Column_Path,Column_Depth,Column_Or der,Column_Intro)Values(@Column_Name,@Parent_ID,@Column_Path,@Column_Depth,@Column_Order,@ Column_Intro)IF @@Error<>0BeginSet @Err=1Goto theEndEnd--更新当前记录之后的记录的ORDER--Update Tb_Column Set Column_Order = Column_Order+1 Where Column_Order> @Column_OrdertheEnd:IF @Err=0BeginCommit TranReturn @Column_IDEndElseBeginRollback TranReturn 0EndGO待续.......删除的存储过程CREATE PROCEDURE sp_Column_Delete(@Column_ID int)ASDeclare @Err As intSet @Err = 0Begin Tran--首先查询该节点下是否有子节点Select Column_ID From Tb_Column Where Parent_ID = @Column_ID IF @@RowCount<>0BeginSet @Err = 1Goto theEndEnd--获取该节点的Column_Order,为了删除后整理其他记录的顺序Declare @Column_Order As intSelect @Column_Order = Column_Order From Tb_Column Where Column_ID = @Colu mn_IDIF @Column_Order Is NUllBeginSet @Err =2Goto theEndEnd--更新其他记录的Column_OrderUpdate Tb_Column Set Column_Order = Column_Order -1 Where Column_Order >@Col umn_OrderIF @@Error<>0BeginSet @Err =3Goto theEndEnd--删除操作Delete From Tb_Column Where Column_ID=@Column_IDIF @@Error<>0BeginSet @Err =4Goto theEndEnd--更新其他记录的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--EndtheEnd:IF @Err = 0BeginCommit TranReturn 0 --删除成功EndElseBeginIF @Err=1BeginRollback TranReturn 1 --有子节点EndElseBeginRollback TranReturn 2--未知错误EndEndGO4.编辑的存储过程（没有用到，我自己写了一个简单的只是编辑名称，没有涉及到移动）CREATE PROCEDURE sp_Column_Update(@Column_ID int,@Parent_ID int,@Column_Name nvarchar(50),@Column_Intro nvarchar(1000))ASDeclare @Err As intSet @Err=0Begin Tran--获取修改前的：Parent_ID,Column_Depth,Column_OrderDeclare @oParent_ID As intDeclare @oColumn_Depth As intDeclare @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_IDIF @oParent_ID Is NullBeginSet @Err = 1Goto theEndEnd--如果父ID没有改变，则直接修改栏目名和栏目简介IF @oParent_ID = @Parent_IDBeginUpdate Tb_Column Set Column_Name = @Column_Name,Column_Intro = @Colu mn_Intro Where Column_ID = @Column_IDIF @@Error <> 0Set @Err = 2Goto theEndEndDeclare @nColumn_Path As nvarchar(1000)Declare @nColumn_Depth As int--获取当前节点作为父节点所包含的节点数[包括自身] 注：如果返回“1” 说明是单节点Declare @theCount As intSelect @theCount = Count(Column_ID) From Tb_Column Where Column_ID=@Column_ ID Or Column_Path like ''+@oColumn_Path+'|%'IF @theCount Is NullBeginSet @Err = 3Goto theEndEndIF @Parent_ID=0 --如果是设置为顶级节点，将节点设置为最后一个顶级节点Begin--Print '设置为顶级栏目'Set @nColumn_Path = Ltrim(Str(@Column_ID))Set @nColumn_Depth =1Select @nColumn_Order = Max(Column_Order) From Tb_ColumnIF @nColumn_Order Is NULLBeginSet @Err = 4Goto theEndEndSet @nColumn_Order = @nColumn_Order - @theCount + 1--更新三部分1 节点本身2 所有子节点2 本树更改之前的后面记录的顺序--Print '更新本栏目之前位置后面的所有栏目[不包括本栏目下的子栏目]的：Column_Order'Update Tb_Column Set Column_Order = Column_Order-@theCount Where (Column_Ord er >@oColumn_Order) And (Column_Path Not like ''+@oColumn_Path+'|%')IF @@Error <> 0BeginSet @Err = 7Goto theEndEnd--Print '更新本栏目的：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 = @Col umn_Name,Column_Intro = @Column_Intro Where Column_ID = @Column_IDIF @@Error <> 0BeginSet @Err = 5Goto theEndEnd--Print '更新本栏目下的所有子栏目的：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_Orde r) Where Column_Path like ''+@oColumn_Path+'|%'IF @@Error <> 0BeginSet @Err = 6Goto theEndEndEndElseBegin--获取未来父节点的相关信息,并设置本节点的相关值Select @nColumn_Depth = Column_Depth,@nColumn_Path = Column_Path From Tb_Co lumn Where Column_ID = @Parent_IDIF @nColumn_Depth Is NULL Or @nColumn_Path Is NullBeginSet @Err = 8Goto theEndEndSet @nColumn_Depth = @nColumn_Depth +1Select @nColumn_Order =Max(Column_Order) From Tb_Column Where Column_ID = @ Parent_ID Or Column_Path like ''+@nColumn_Path+'|%'IF @nColumn_Order Is NULLBeginSet @Err = 9Goto theEndEndSet @nColumn_Path = @nColumn_Path +'|'+ Ltrim(Str(@Column_ID))IF @nColumn_Order = @oColumn_Order+1 --如果新的父节点是原来位置上端最近一个兄弟,则所有节点的顺序都不改变BeginUpdate Tb_Column Set Parent_ID=@Parent_ID,Column_Path = @nColumn_Path,Column _Depth = @nColumn_Depth, Column_Name = @Column_Name,Column_Intro = @Colu mn_Intro Where Column_ID = @Column_IDIF @@Error <> 0BeginSet @Err = 10Goto theEndEndEndSet@nColumn_Order = @nColumn_Order + 1--更新三部分1 本树更改之前的后面（或前面）记录的顺序1 节点本身 3 所有子节点--分为向上移或象下移--Print '更新本栏目之前位置后面的所有栏目[或者本栏目之后位置][不包括本栏目下的子栏目]的：C olumn_Order'IF @nColumn_Order < @oColumn_OrderBeginUpdate Tb_Column Set Column_Order = Column_Order+@theCount Where Column_Ord er<@oColumn_Order And Column_Order >=@nColumn_Order And (Column_Path Not like ''+@oColumn_Path+'|%') And Column_ID<>@Column_IDIF @@Error <> 0BeginSet @Err = 12Goto theEndEndEndElseBeginUpdate Tb_Column Set Column_Order = Column_Order-@theCount Where Column_Orde r >@oColumn_Order And Column_Order<@nColumn_Order And (Column_Path Not lik e ''+@oColumn_Path+'|%') And Column_ID<>@Column_IDIF @@Error <> 0BeginSet @Err = 13Goto theEndEnd--Print '更新本栏目的：Parent_ID,Column_Path,Column_Depth,Column_Order,Column_Name, Column_Intro'Print 'Order : '+Ltrim(Str(@nColumn_Order))IF @nColumn_Order > @oColumn_OrderSet @nColumn_Order = @nColumn_Order - @theCountUpdate Tb_Column Set Parent_ID=@Parent_ID,Column_Path = @nColumn_Path,Column _Depth = @nColumn_Depth,Column_Order = @nColumn_Order, Column_Name = @Col umn_Name,Column_Intro = @Column_Intro Where Column_ID = @Column_IDIF @@Error <> 0BeginSet @Err = 10Goto theEndEnd--Print '更新本栏目下的所有子栏目的：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 <> 0BeginSet @Err = 11EndEndtheEnd:IF @Err<>0 --如果有错误则返回错误号BeginRollback TranReturn @ErrEndElse--如果没有错误就返回0BeginCommit TranReturn 0EndGO待续..................最后一步显示分类（只是一条select语句）CREATE PROCEDURE sp_Column_ListASSELECT Column_ID, Column_Name, Parent_ID, Column_Path, Column_Depth, Column_Order, Column_IntroFROM Tb_ColumnORDER BY Column_OrderGO接下来就是在界面呈现了，显示的时候用的是DataGridHtml代码如下：<ASP:DataGrid id="DataGrid1" runat="server" AutoGenerateColumns="False" Width="52 0px" DataKeyField="Column_Id"><Columns><asp:TemplateColu mn HeaderText="分类信息"><ItemTempl ate><asp: Label id="lbname" runat="server"></asp:Label></ItemTemp late><EditItemTe mplate><asp: TextBox id="tbdgname" runat="server" Text='<%#DataBinder.Eval(Container.DataItem, "Column_Name")%>'></as p:TextBox></EditItemT emplate></asp:TemplateColu mn><asp:TemplateColu mn HeaderText="添加子节点"><ItemTempl ate><a h ref="#" onclick="Open('AddSonCate.aspx?fid=<%#DataBinder.Eval(Container.DataItem," Column_Id")%>','son',280,80)">添加子分类</a></ItemTemp late></asp:TemplateColu mn><asp:TemplateColu mn HeaderText="编辑"><ItemTempl ate><asp: LinkButton runat="server" Text="编辑" CommandName="Edit" CausesValidation="false"> </asp:LinkButton></ItemTemp late><EditItemTe mplate><asp:LinkButton runat="server" Text="更新" CommandName="Update" CausesValidation="Fals e"></asp:LinkButton>&nbsp;<asp: LinkButton runat="server" Text="取消" CommandName="Cancel" CausesValidation="fals e"></asp:LinkButton></EditItemT emplate></asp:TemplateColu mn><asp:TemplateColu mn HeaderText="删除"><ItemTempl ate><asp: LinkButton runat="server" ID="lbdelete" Text="删除" CommandName="Delete" CausesV alidation="false" CommandArgument='<%#DataBinder.Eval(Container.DataItem,"Column _Id")%>'></as p:LinkButton></ItemTemp late></asp:TemplateColu mn></Columns></asp:DataGrid>最关键的地方在DataGrid_ItemDataBind事件中private void DataGrid1_ItemDataBound(object sender, System.Web.UI.WebControls.Data GridItemEventArgs e){if(e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem){//得到Column_Name字段的值string columnName = (string)DataBinder.Eval(e.Item.DataI tem,"Column_Name");string columnTemp = "";//得到深度值Column_Depthint columnDepth = Int32.Parse(DataBinder.Eval(e.Item.Dat aItem,"Column_Depth").ToString());if(columnDepth>1){for(int i = 1;i<columnDepth;i++){columnTemp +="&nbsp;&nbsp;&nbsp;&nbs p;";}columnTemp+="┝";}Label lbname = (Label)e.Item.FindControl("lbname");lbname.Text = columnTemp+columnName ;LinkButton lbdelete = (LinkButton)e.Item.FindControl("lbde lete");lbdelete.Attributes.Add("OnClick","JavaScript:return confirm ('确实要删掉此分类吗？');");}}Over!。