unit1.pas

《Delphi7编程100例》代码,书配资料

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DB, DBTables, Grids, DBGrids, StdCtrls, ExtCtrls, DBCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    Table1: TTable;
    Query1: TQuery;
    DataSource2: TDataSource;
    DBNavigator1: TDBNavigator;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  DBNavigator1.DataSource:=DataSource1;
  DBGrid1.DataSource:=DataSource1;
  with Table1 do
  begin
    Open;
    Setkey;
    KeyExclusive:=True;// 为True时不包括边界值，为False时包括边界值，缺省为False;
    SetRangeStart;
    Fieldbyname('CustNo').AsString:='1000'; //设定范围上界
    SetRangeEnd;
    FieldbyName('CustNo').AsString:='2500'; //设定范围下界
    ApplyRange; //使范围生效
    Refresh;
  end;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  DBNavigator1.DataSource:=DataSource1;
  DBGrid1.DataSource:=DataSource1;
  Table1.Filter:='(CustNo>1500) and (CustNo<2500)';
  Table1.Filtered:=True;
  Table1.Open;
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  DBNavigator1.DataSource:=DataSource2;
  DBGrid1.DataSource:=DataSource2;
  Query1.Open;
end;

end.