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delphi KbmMemTable的简单应用(增删改查示例)

作者:admin 来源: 日期:2018/1/16 7:37:43 人气: 标签:KbmMem****

KbmMemTable是一款高效且强大的内存表控件,内存表顾名思义其最大的优势就是速度,KbmMemTable不仅完美地实现了高效的特征,同时,最新版本还支持索引、SQL语句等高级用法。其用法超简单,基本用法和ClientDataSet一致,以下是我简单的应用示例,实现了增删改查等基本功能:

 

unit Unit1;

 

interface

 

uses

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

  Dialogs, Grids, DBGrids, DB, StdCtrls, kbmMemTable;

 

type

  TForm1 = class(TForm)

    Button1: TButton;

    DataSource1: TDataSource;

    DBGrid1: TDBGrid;

    Button2: TButton;

    Button3: TButton;

    Button4: TButton;

    Button5: TButton;

    Button6: TButton;

    Button7: TButton;

    procedure Button1Click(Sender: TObject);

    procedure FormCreate(Sender: TObject);

    procedure Button2Click(Sender: TObject);

    procedure Button4Click(Sender: TObject);

    procedure Button3Click(Sender: TObject);

    procedure Button5Click(Sender: TObject);

    procedure Button6Click(Sender: TObject);

    procedure Button7Click(Sender: TObject);

  private

    { Private declarations }

  public

    { Public declarations }

  end;

 

var

  Form1: TForm1;

  kbmMemTable1 : TkbmMemTable;

  Id:Integer;

 

implementation

 

{$R *.dfm}

 

procedure TForm1.Button1Click(Sender: TObject);

begin

  //建表

  kbmMemTable1.FieldDefs.Clear;

  kbmMemTable1.FieldDefs.Add('Id', ftInteger, 0, False);

  kbmMemTable1.FieldDefs.Add('Value', FtString, 20, False);

  kbmMemTable1.FieldDefs.Add('Time', ftDateTime, 0, False);

  kbmMemTable1.IndexDefs.Add('Index1','Id',[]);//定义索引

  kbmMemTable1.CreateTable;

  kbmMemTable1.Active := True;

end;

 

procedure TForm1.Button2Click(Sender: TObject);

var

  fld_Id:TIntegerField;

  fld_Value:TStringField;

  fld_Time:TDateTimeField;

  i:Integer;

begin

  //插入

  with kbmMemTable1 do

  begin

    DisableControls; //切断数据感知控件

    try

      Open; //打开

      //定义Field

      fld_Id:=TIntegerField(FieldByName('Id'));

      fld_Value:=TStringField(FieldByName('Value'));

      fld_Time:=TDateTimeField(FieldByName('Time'));

      for i := 0 to 9 do

      begin

        Inc(Id);

        Append; //附加数据

        //赋值

        fld_Id.AsInteger := Id;

        fld_Value.AsString := 'Hello PFeng!'+inttostr(Id);

        fld_Time.AsDateTime := Now;

        Post; //确定

      end;

      UpdateIndexes;//更新索引

    finally

      EnableControls; //连接数据感知控件

    end;

  end;

end;

 

procedure TForm1.Button3Click(Sender: TObject);

var

  fld_Id:TIntegerField;

  fld_Value:TStringField;

  fld_Time:TDateTimeField;

begin

  //更新

  with kbmMemTable1 do

  begin

    Open;

    fld_Id:=TIntegerField(FieldByName('Id'));

    fld_Value:=TStringField(FieldByName('Value'));

    fld_Time:=TDateTimeField(FieldByName('Time'));

    if Locate('Id',5,[]) then

    begin

      Edit;

      fld_Value.AsString := '内容被修改';

      fld_Time.AsDateTime := Now;

      Post;

    end;

  end;

end;

 

procedure TForm1.Button4Click(Sender: TObject);

var

  fld_Id:TIntegerField;

  fld_Value:TStringField;

  fld_Time:TDateTimeField;

begin

  //查询

  with kbmMemTable1 do

  begin

    Open;

    fld_Id:=TIntegerField(FieldByName('Id'));

    fld_Value:=TStringField(FieldByName('Value'));

    fld_Time:=TDateTimeField(FieldByName('Time'));

    if Locate('Id',5,[]) then

    ShowMessage(fld_Value.AsString);

    //还可以用FindKey实现,结合索引速度更快

    // kbmMemTable1.IndexFieldNames:='Id';

    // if kbmMemtable1.FindKey([5]) then ...

  end;

end;

 

procedure TForm1.Button5Click(Sender: TObject);

var

  fld_Id:TIntegerField;

  fld_Value:TStringField;

  fld_Time:TDateTimeField;

begin

  //删除

  with kbmMemTable1 do

  begin

    Open;

    fld_Id:=TIntegerField(FieldByName('Id'));

    fld_Value:=TStringField(FieldByName('Value'));

    fld_Time:=TDateTimeField(FieldByName('Time'));

    if Locate('Id',5,[]) then

    begin

      Delete;

      UpdateIndexes;

    end;

  end;

end;

 

procedure TForm1.Button6Click(Sender: TObject);

var

  fld_Id:TIntegerField;

  fld_Value:TStringField;

  fld_Time:TDateTimeField;

  id:Integer;

begin

  //循环比较最小值

  with kbmMemTable1 do

  begin

    Open;

    fld_Id:=TIntegerField(FieldByName('Id'));

    fld_Value:=TStringField(FieldByName('Value'));

    fld_Time:=TDateTimeField(FieldByName('Time'));

    DisableControls;

    try

      First;

      id := fld_Id.AsInteger;

      while not Eof do

      begin

        if id > fld_Id.AsInteger then

        id := fld_Id.AsInteger;

        Next;

      end;

      Locate('Id',id,[]);

    finally

      EnableControls;

    end;

  end;

end;

 

procedure TForm1.Button7Click(Sender: TObject);

begin

  //清空

  kbmMemTable1.EmptyTable;

end;

 

procedure TForm1.FormCreate(Sender: TObject);

begin

  kbmMemTable1 := TkbmMemTable.Create(Self);

  DataSource1.DataSet := kbmMemTable1;

end;

 

end.

 

来源:http://www.pfeng.org/archives/372


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