delphi7 treeview + 数据库实现动态节点维护

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;

interface

uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls, ComCtrls, ShellAPI, DB, ADODB;

type

  TForm1 = 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;

var

  Form1: 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nil

     qry   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);

var

  sql, 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 then

  begin

    if fnode = nil then

      fdwbh := nilfjdbh

    else

      fdwbh := 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 do

      begin

        newnode := 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 then

        node := tv.Items.GetFirstNode

      else

        node := 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

    begin

      node := fnode.GetNext;

      if node <> nil then

        addChildNodes(tv, node, qry, tab, jdbh, jdmc, fjdbh, nilfjdbh);

    end;

  end;

end;

procedure addChildNodes(tv: TTreeView; fnode: TTreeNode; qry: TADOQuery);

var

  fdwbh: Integer;

  sql: string;

  node, newnode: TTreeNode;

  Pdata: ^Integer;

begin

  if fnode = nil then

    fdwbh :=

  else

    fdwbh := 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 do

    begin

      newnode := 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 then

      node := tv.Items.GetFirstNode

    else

      node := 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

  begin

    node := fnode.GetNext;

    if node <> nil then

      addChildNodes(tv, node, qry);

  end;

end;

procedure TForm1.btn_addtjClick(Sender: TObject);

var

  jdmc, sql: string;

  fdwbh: integer;

  node, newnode: TTreeNode;

  pinteger: ^integer;

begin

  try

    node := tv1.Selected;

    jdmc := edt_jdmc.text;

    newnode := tv1.Items.add(node, jdmc);

    maxdwbh := maxdwbh + ;

    New(pinteger);

    pinteger^ := maxdwbh;

    newnode.data := pinteger;

    if node = nil then

      fdwbh :=

    else if node.Level =  then

      fdwbh :=

    else

      fdwbh := 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！');

  except

    on e: Exception do

      ShowMessage(e.Message);

  end;

end;

procedure TForm1.btn_addzjdClick(Sender: TObject);

var

  jdmc, sql: string;

  fdwbh: integer;

  node, newnode: TTreeNode;

  pinteger: ^integer;

begin

  try

    jdmc := edt_jdmc.text;

    node := tv1.Selected;

    newnode := tv1.Items.AddChild(node, jdmc);

    maxdwbh := maxdwbh + ;

    New(pinteger);

    pinteger^ := maxdwbh;

    newnode.Data := pinteger;

    if node = nil then

      Exit

    else

      fdwbh := 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！');

  except

    on e: Exception do

      ShowMessage(e.Message);

  end;

end;

procedure TForm1.btn_delClick(Sender: TObject);

var

  node: TTreeNode;

  dwbh: integer;

  sql: string;

begin

  try

    node := 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;

  except

    on e: Exception do

      ShowMessage(e.Message);

  end;

end;

procedure TForm1.btn_xsClick(Sender: TObject);

begin

  try

    tv1.Items.Clear;

    addChildNodes(tv1, nil, qry1, 'zzjgbmb', 'dwbh', 'dwmc', 'fdwbh', '');

  except

    on e: Exception do

      ShowMessage(e.Message);

  end;

end;

procedure TForm1.FormCreate(Sender: TObject);

var

  sql: string;

begin

  try

    maxdwbh := ;

    sql := 'select max(dwbh) maxdwbh from zzjgbmb';

    qry1.Close;

    qry1.SQL.Clear;

    qry1.SQL.Add(sql);

    qry1.Open;

    if not qry1.isempty then

    begin

      qry1.First;

      maxdwbh := qry1.fieldbyname('maxdwbh').AsInteger;

    end;

  except

    on e: Exception do

      showmessage(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

begin

  declare @tmp1 table (dwbh int)

  declare @tmp2 table (dwbh int)

  declare @tmp3 table (dwbh int)

  insert into @tmp1 select dwbh from zzjgbmb where fdwbh=@dwbh

  insert into @tmp3 select dwbh from @tmp1

  while exists(select dwbh from zzjgbmb where fdwbh in (select dwbh from @tmp1))

  begin

    delete @tmp2

    insert into @tmp2 select dwbh from zzjgbmb where fdwbh in (select dwbh from @tmp1)

    delete @tmp1

    insert 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

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delphi7 treeview + 数据库实现动态节点维护

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巴特西

delphi7 treeview + 数据库 实现动态节点维护

最新文章

热门文章

delphi7 treeview + 数据库实现动态节点维护