unit1.~pas

本光盘是《Delphi 7应用教程》一书的配套光盘

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Query1: TQuery;
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    Edit1: TEdit;
    Edit2: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
Var
   Curdir:string;
begin
   Getdir(0,CurDir);
   Query1.DatabaseName :=Curdir;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  Query1.SQL.Clear ;   //清除SQL属性中原来的语句
  Query1.SQL.Add('Select * From 通讯录'); //以下两条语句用来给SQL属性添加新的SQL语句
  Query1.SQL.Add('Where 出生日期>=:D1 AND 出生日期<=:D2'); //两个参数D1和D2
  Query1.Params[0].AsDate  :=strtodate(Edit1.Text) ;  //通过Params属性给参数赋值
  Query1.ParamByName('D2').AsDate :=StrToDate(Edit2.Text) ; //通过ParamByName方法给属性赋值
  Query1.Prepare ;   //优化
  Query1.Open ;  //执行SQL语句，打开记录集
end;

end.