树形问题(简单问题)

Question

比如我有个表table1  id name node
1  A     null
2  B     null
3  V     B
4  G     B
5  A1    A
6  A2    A
7  a3    A
8  K     NULL
现在我想把他显示在TREEVIEW上面
点写代码啊？各位告诉显示成
  A
    A1
    A2
    A3
  B
    V
    G
  K

Answer 1

循环吧先筛选出 node=null的记录,然后添加到treeview,然后循环这几条记录,选出node=节点text的记录,再添加到treeview,依次类推建议
第一次只筛选node=null的记录,然后在treeview的expanding事件中再查找属于他的子记录,类似于windows的资源管理器再有,数据库的设计建议如下id  pid  name  code(如果需要)pid为父级记录的id

Answer 2

这样应该行了,有点问题自己改改
procedure TForm1.FindLeechDom(Leechdomname: String;node: TTreeNode);
var
  temp: TQuery;
  node1: TTreeNode;
begin
  Try
    temp := TQuery.Create(Self);
    temp.DatabaseName := ExtractFilePath(Application.ExeName);
    With temp do
    begin
      Close;
      SQL.Clear;
      SQL.Add('select * from table1 where node = :Value');
      ParamByName('value').AsString := id;
      Open;
    end;
    while Not Temp.Eof do
    begin
      node1 := TreeView1.Items.AddChild(node,temp.FieldByName('name').AsString);
      FindLeechDom(temp.FieldByName('name').AsString,node1);
      temp.Next;
    end;
  Finally
    temp.Free;
  end;
end;
procedure TForm1.FormCreate(Sender: TObject);
var
  temp: TTreeNode;
begin
    With Query1 do
    begin
      Close;
      SQL.Clear;
      SQL.Add('select * from table1');
      Open;
    end;
    while not Query1.Eof do
    begin
      if Query1.FieldByName('node').AsString = '' then
      begin
        temp := TreeView1.Items.AddChild(TreeView1.Items[0],Query1.FieldByName('name').AsString);
        FindLeechDom(Query1.FieldByName('name').AsString,temp);
      end;
      Query1.Next;
    end;
end;

Answer 3

定义 q 为数据集 q.clear; 
q.sql.text := 'select * from table1 where code is null' 
q.open; 
while not q.eof do 
begin 
  //名称添加到treeview(应该会吧) 
    q.Next; 
end; 这样就选出了第一级节点 
然后在treeview的expanding事件中 procedure TForm1.TreeView1Expanding(Sender: TObject; Node: TTreeNode; 
  var AllowExpansion: Boolean); 
begin 
  q.close; 
  q.sql.text := 'select * from table1 where code='+QuotedStr(NOde.Text); 
  q.open; 
  while not q.eof do 
  begin 
    //名称添加到Node的自节点(应该会吧) 
    q.Next; 
  end; 
end;

Answer 4

fyiprocedure TRES_BOM_VIEW_F.btnSB_SearchClick(Sender: TObject);//點擊按鈕生成樹的過程
begin
  inherited;
  try
    RES_LOADING_F:=TRES_LOADING_F.Create(Self);
    RES_LOADING_F.Label1.Caption:='正在檢索相關數據......';
    RES_LOADING_F.Show;
    RES_LOADING_F.Update;
    CREATETREEVIEWMODEL;//過程名
  finally
    RES_LOADING_F.Close;
  end;
end;procedure TRES_BOM_VIEW_F.CREATETREEVIEWMODEL;
var
  iLoop:Integer;
  Master,MasterNode:TTreeNode;
begin
  adoq_getop.Close;
  //SELECT distinct PARN_TYP FROM WWW where parn_typ<>'.' and parn_typ is not null order by PARN_TYP desc
  adoq_getop.SQL.Text:='SELECT distinct PARN_TYP FROM WWW where parn_typ<>''.'' and parn_typ is not null order by PARN_TYP desc';
  adoq_getop.Open;
  adoq_getop.First;
  cx_TV.Items.BeginUpdate;
  cx_TV.Items.Clear;
  Master:=cx_TV.Items.Add(nil,'昆盈BOM表檢視');
  while not adoq_getop.Eof do
  begin
    if adoq_getop.FieldByName('PARN_TYP').AsString<>'' then
    begin
      Screen.Cursor:=crSQLWait;
      MasterNode:=cx_TV.Items.AddChild(Master,VarToStr(adoq_getop.FieldValues['PARN_TYP']));
      Application.ProcessMessages;
      qry_op.Close;
      qry_op.SQL.Text:='SELECT DISTINCT PARN_LITM FROM WWW WHERE PARN_TYP='''+ VarToStr(adoq_getop.FieldValues['PARN_TYP'])+''' GROUP BY PARN_LITM';
      qry_op.Open;
      for iLoop:=0 to qry_op.RecordCount -1 do
      begin
        cx_TV.Items.AddChild(MasterNode,VarToStr(qry_op.FieldValues['PARN_LITM']));
        qry_op.Next;
      end;
      Application.ProcessMessages;
      cx_TV.Items.EndUpdate;
      Screen.Cursor:=crDefault;
    end;
    adoq_getop.Next;
    Application.ProcessMessages;
  end;
 {
  ThreadTView:=cx_TV;
  ViewThread:=TExpandLH.Create;
  ViewThread.Resume;
  }
end;多層可用遞歸生成:
private
    procedure CreateTreeModel;
    procedure CreateSubTree(isR:boolean;FNodeName:string;Node:TTreeNode=nil);
 { Private declarations }procedure TForm1.CreateTreeModel;
var
  iLoop:Integer;
  aa:TTreeNode;
begin
  ADOQuery1.Close;
  ADOQuery1.SQL.Text:='SELECT PARN_TYP FROM bom GROUP BY PARN_TYP';
  ADOQuery1.Open;
  ADOQuery1.First;
  TreeView1.Items.BeginUpdate;
  TreeView1.Items.Clear;
  aa:=TreeView1.Items.Add(nil,'BOM');
  Screen.Cursor:=crSQLWait;
  Application.ProcessMessages;
  for iLoop:=0 to ADOQuery1.RecordCount -1 do
  begin
    TreeView1.Items.AddChild(aa,VarToStr(ADOQuery1.FieldValues['PARN_TYP']));
    ADOQuery1.Next;
  end;
  Application.ProcessMessages;
  TreeView1.Items.EndUpdate;
  TreeView1.Items[0].Expand(False);
  Screen.Cursor:=crDefault;
end;procedure TForm1.CreateSubTree(isR:boolean;FNodeName:string;Node:TTreeNode=nil);
var
  mLocalName:string;
  TreeNode:TTreeNode;
  Ads_Tmp,adoq_op:TADODataSet;
begin
    if isR then
    begin
      Ads_Tmp:=TADODataSet.Create(Self);
      Ads_Tmp.Connection:=ADOConnection1;
      with Ads_Tmp do
      try
        Close;
        //CommandText:='Select distinct PARN_LITM from bom Where PARN_TYP ='+'''' + FNodeName+'''';
        CommandText:='Select distinct PARN_LITM from bom Where PARN_TYP ='+'''' + FNodeName+''' and PARN_LITM like ''3%''';
        Open;
        First;
        TreeView1.Items.BeginUpdate;
        Screen.Cursor:=crSQLWait;
        Application.ProcessMessages;
         while not Eof do
         begin
           mLocalName:=Trim(FieldbyName('PARN_LITM').Asstring);
           TreeNode:=TreeView1.Items.AddChild(Node,Trim(FieldByName('PARN_LITM').AsString));
           CreateSubTree(False,mLocalName,TreeNode);
           Next;
         end;
         Application.ProcessMessages;
         TreeView1.Items.EndUpdate;
         Screen.Cursor:=crDefault;
        finally
          Ads_Tmp.Free;
        end;
      end
      else
      begin
          adoq_op:=TADODataSet.Create(Self);
          adoq_op.Connection:=ADOConnection1;
          with adoq_op do
          try
            Close;
            CommandText:='Select CHLD_LITM from bom Where PARN_TYP='+''''+sTmp+''''+' and  PARN_LITM ='+'''' + FNodeName+''''+' group by CHLD_LITM';
            Open;
            First;
            TreeView1.Items.BeginUpdate;
            Screen.Cursor:=crSQLWait;
            Application.ProcessMessages;
            while not Eof do
             begin
               mLocalName:=Trim(FieldbyName('CHLD_LITM').Asstring);
               TreeNode:=TreeView1.Items.AddChild(Node, Trim(FieldByName('CHLD_LITM').AsString));
               CreateSubTree(False,mLocalName,TreeNode);
               Next;
             end;
             Application.ProcessMessages;
             TreeView1.Items.EndUpdate;
             Screen.Cursor:=crDefault;
            finally
              adoq_op.Free;
            end;
      end;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
  sTmp:=TreeView1.Selected.Text;
  CreateSubTree(True,TreeView1.Selected.Text,TreeView1.Selected);
end;

Answer 5

procedure InitTree(Tree:TTreeView); 
var 
  Root:TTreeNode; 
  RootQy:Tadoquery; 
  procedure CreateChild(node:TTreeNode;nodeName:string); 
  var 
    tempNode:TTreeNode; 
    tempQy:Tadoquery; 
  begin 
    tempQy:=Tadoquery.create(application); 
    tempQy.Connection:=ADOConnection1; 
    tempQy.SQL.Text:='select * from 表 where Node <>null and node='''+nodeName+''''; 
    tempQy.Open; 
    while not tempQy.Eof do 
    begin 
      tempNode:=Tree.Items.AddChild(node,tempQy.FieldValues['Name']); 
      CreateChild(tempNode,tempQy.FieldValues['Name']); 
    end; 
  end; 
begin 
  RootQy:=Tadoquery.create(application); 
  RootQy.Connection:=ADOConnection1; 
  RootQy.SQL.Text:='select * from 表 where Node=null'; 
  Rootqy.Open; 
  while not Rootqy.Eof do 
  begin 
    Root:=Tree.Items.AddFirst(nil,Rootqy.FieldValues['name']); 
    CreateChild(Root,Rootqy.FieldValues['name']); 
    Rootqy.Next; 
  end; 
end; procedure TForm1.Button1Click(Sender: TObject); 
begin 
  InitTree(TreeView1); 
end;