首先说下树节点对应的表的基本结构,必需要有的字段(节点编号,父节点编号,节点名称),其他字段根据你开发的需要添加
从添加节点开始,一开始就取出表中最大节点编号,每次添加节点的时候,该节点编号增加1;
添加节点的时候我们有2个步骤,首先是给treeview树种建立节点;其次是给数据库中添加相应的节点记录;
添加节点树的时候,需要注意的是要把该节点的节点编号加入到该节点的data属性中.
在数据库中加入节点记录的时候,节点编号和父节点编号都不能少,如果是第0层节点,那么该节点的父节点编号是'0'(这种情况你自己定义,我在这里设为'0')
显示节点我写了一个通用函数来实现的
删除节点由于要删除该节点及其所有后代节点在表中的记录,这个在sql server中好像没有什么好的语句,我写了一个存储过程来实现的
unit Unit1;interfaceusesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, StdCtrls, ComCtrls, ShellAPI, DB, ADODB;typeTForm1 = class(TForm)tv1: TTreeView;btn_addtj: TButton;btn_addzjd: TButton;btn_del: TButton;edt_jdmc: TEdit;Label1: TLabel;btn_xs: TButton;con1: TADOConnection;qry1: TADOQuery;qry2: TADOQuery;procedure btn_addtjClick(Sender: TObject);procedure btn_addzjdClick(Sender: TObject);procedure btn_delClick(Sender: TObject);procedure btn_xsClick(Sender: TObject);procedure FormCreate(Sender: TObject);private{ Private declarations }public{ Public declarations }end;varForm1: TForm1;maxdwbh: integer; procedure addChildNodes(tv: TTreeView; fnode: TTreeNode; qry: TADOQuery); overload; procedure addChildNodes(tv: TTreeView; fnode: TTreeNode; qry: TADOQuery; tab, jdbh, jdmc, fjdbh, nilfjdbh: string); overload; implementation{$R *.dfm} { 功能:在一个treeview中显示数据库中父子节点,并且把节点的编号存入自己的data属性中 参数:tv 展示树fnode 表示tv中的节点,第一次调用通常这个节点取nilqry 一个ADOQuery控件,用来做查询tab 我们的父子节点存放的数据库表名称jdbh tab中节点编号代表的字段名称jdmc tab中节点名称代表的字段名称fjdbh tab中父节点编号代表的字段名称nilfjdbh 树中第0级节点的父节点字段给分配的值 注意:我们的树在添加(子)节点的时候也要把它的节点的编号存入到该节点的data属性中 }procedure addChildNodes(tv: TTreeView; fnode: TTreeNode; qry: TADOQuery; tab, jdbh, jdmc, fjdbh, nilfjdbh: string); varsql, fdwbh: string;node, newnode: TTreeNode;pinteger: ^string; begin//判断表中有没有节点,如果连第0级节点都不存在,我们也就不需要显示树了sql := 'select * from tab where fjdbh=''' + nilfjdbh + '''';qry.Close;qry.SQL.Clear;qry.SQL.Add(sql);qry.Open;if not qry.IsEmpty thenbeginif fnode = nil thenfdwbh := nilfjdbhelsefdwbh := string(fnode.data^);//取出节点fnode的全部子节点的记录sql := 'select ' + jdbh + ',' + jdmc + ',' + fjdbh + ' from ' + tab + ' where ' + fjdbh + '=''' + fdwbh + ''' order by ' + jdbh;qry.Close;qry.SQL.Clear;qry.SQL.Add(sql);qry.Open;//树中加入子节点if not qry.IsEmpty then //有子节点begin//添加一个节点的所有子节点qry.First;while not qry.Eof dobeginnewnode := tv.Items.AddChild(fnode, qry.fieldbyname(jdmc).AsString);New(pinteger);pinteger^ := qry.fieldbyname(jdbh).AsString;newnode.Data := pinteger;qry.Next;end;//定位下一个该操作的节点if fnode = nil thennode := tv.Items.GetFirstNodeelsenode := fnode.getFirstChild;//递归调用对下一个子节点进行同样的操作addChildNodes(tv, node, qry, tab, jdbh, jdmc, fjdbh, nilfjdbh);end else //没有子节点的情况,取它的下一个兄弟节点递归调用beginnode := fnode.GetNext;if node <> nil thenaddChildNodes(tv, node, qry, tab, jdbh, jdmc, fjdbh, nilfjdbh);end;end; end;procedure addChildNodes(tv: TTreeView; fnode: TTreeNode; qry: TADOQuery); varfdwbh: Integer;sql: string;node, newnode: TTreeNode;Pdata: ^Integer; beginif fnode = nil thenfdwbh := 0elsefdwbh := Integer(fnode.data^);//取出节点fnode的全部子节点的记录sql := 'select dwbh,dwmc,fdwbh from zzjgbmb where fdwbh=' + inttostr(fdwbh) + ' order by dwbh';qry.Close;qry.SQL.Clear;qry.SQL.Add(sql);qry.Open;//树中加入子节点if not qry.IsEmpty then //有子节点begin//添加一个节点的所有子节点qry.First;while not qry.Eof dobeginnewnode := tv.Items.AddChild(fnode, qry.fieldbyname('dwmc').AsString);New(Pdata);Pdata^ := qry.fieldbyname('dwbh').AsInteger;newnode.Data := Pdata;qry.Next;end;//定位下一个该操作的节点if fnode = nil thennode := tv.Items.GetFirstNodeelsenode := fnode.getFirstChild;//递归调用对下一个节点进行同样的操作addChildNodes(tv, node, qry);end else //没有子节点的情况beginnode := fnode.GetNext;if node <> nil thenaddChildNodes(tv, node, qry);end; end;procedure TForm1.btn_addtjClick(Sender: TObject); varjdmc, sql: string;fdwbh: integer;node, newnode: TTreeNode;pinteger: ^integer; begintrynode := tv1.Selected;jdmc := edt_jdmc.text;newnode := tv1.Items.add(node, jdmc);maxdwbh := maxdwbh + 1;New(pinteger);pinteger^ := maxdwbh;newnode.data := pinteger;if node = nil thenfdwbh := 0else if node.Level = 0 thenfdwbh := 0elsefdwbh := Integer(node.Parent.data^);sql := 'insert into zzjgbmb(dwbh,fdwbh,dwmc) values(' + inttostr(maxdwbh) + ',' + inttostr(fdwbh) + ',''' + jdmc + ''')';qry1.Close;qry1.SQL.Clear;qry1.SQL.Add(sql);qry1.ExecSQL;ShowMessage('单位"' + jdmc + '"添加成功！');excepton e: Exception doShowMessage(e.Message);end; end;procedure TForm1.btn_addzjdClick(Sender: TObject); varjdmc, sql: string;fdwbh: integer;node, newnode: TTreeNode;pinteger: ^integer; begintryjdmc := edt_jdmc.text;node := tv1.Selected;newnode := tv1.Items.AddChild(node, jdmc);maxdwbh := maxdwbh + 1;New(pinteger);pinteger^ := maxdwbh;newnode.Data := pinteger;if node = nil thenExitelsefdwbh := Integer(node.data^);sql := 'insert into zzjgbmb(dwbh,fdwbh,dwmc) values(' + inttostr(maxdwbh) + ',' + inttostr(fdwbh) + ',''' + jdmc + ''')';qry1.Close;qry1.SQL.Clear;qry1.SQL.Add(sql);qry1.ExecSQL;ShowMessage('单位"' + jdmc + '"添加成功！');excepton e: Exception doShowMessage(e.Message);end; end;procedure TForm1.btn_delClick(Sender: TObject); varnode: TTreeNode;dwbh: integer;sql: string; begintrynode := tv1.Selected;node.Delete;dwbh := Integer(node.data^);sql := 'exec p_zzjgbmb_delnode ' + inttostr(dwbh);qry1.Close;qry1.SQL.Clear;qry1.SQL.Add(sql);qry1.ExecSQL;excepton e: Exception doShowMessage(e.Message);end; end;procedure TForm1.btn_xsClick(Sender: TObject); begintrytv1.Items.Clear;addChildNodes(tv1, nil, qry1, 'zzjgbmb', 'dwbh', 'dwmc', 'fdwbh', '0');excepton e: Exception doShowMessage(e.Message);end; end;procedure TForm1.FormCreate(Sender: TObject); varsql: string; begintrymaxdwbh := 0;sql := 'select max(dwbh) maxdwbh from zzjgbmb';qry1.Close;qry1.SQL.Clear;qry1.SQL.Add(sql);qry1.Open;if not qry1.isempty thenbeginqry1.First;maxdwbh := qry1.fieldbyname('maxdwbh').AsInteger;end;excepton e: Exception doshowmessage(e.message);end; end;end.
删除节点及其后代节点的存储过程
create procedure [dbo].[p_zzjgbmb_delnode](@dwbh int) as begindeclare @tmp1 table (dwbh int)declare @tmp2 table (dwbh int)declare @tmp3 table (dwbh int)insert into @tmp1 select dwbh from zzjgbmb where fdwbh=@dwbhinsert into @tmp3 select dwbh from @tmp1while exists(select dwbh from zzjgbmb where fdwbh in (select dwbh from @tmp1))begindelete @tmp2insert into @tmp2 select dwbh from zzjgbmb where fdwbh in (select dwbh from @tmp1) delete @tmp1insert into @tmp1 select dwbh from @tmp2 insert into @tmp3 select dwbh from @tmp1 end delete from zzjgbmb where dwbh in (select dwbh from @tmp3); delete from zzjgbmb where dwbh = @dwbh end
简单的界面
