datalocate.pas

《delphi数据库设计与实例开发》随书光盘

unit DataLocate;

interface

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

type
  TForm1 = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Label5: TLabel;
    Label6: TLabel;
    GroupBox1: TGroupBox;
    Label7: TLabel;
    Label8: TLabel;
    Edit7: TEdit;
    Edit8: TEdit;
    Button1: TButton;
    Button2: TButton;
    GroupBox2: TGroupBox;
    Table1: TTable;
    Label9: TLabel;
    Edit9: TEdit;
    Button3: TButton;
    Button4: TButton;
    GroupBox3: TGroupBox;
    Label10: TLabel;
    Edit10: TEdit;
    Button5: TButton;
    DBEdit1: TDBEdit;
    DBEdit2: TDBEdit;
    DBEdit3: TDBEdit;
    DBEdit4: TDBEdit;
    DBEdit5: TDBEdit;
    DBEdit6: TDBEdit;
    DataSource1: TDataSource;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
 with Table1 do
  begin
   if IndexFieldNames='' then
   IndexFieldNames:='LastName;FirstName';//设置索引字段
   SetKey; //进入查询状态
   FieldByName('LastName').AsString:=edit7.text;
   FieldByName('FirstName').AsString:=edit8.text;
  {给查找字段的关键字赋值}
   if GotoKey then //执行查找
    Showmessage('查找成功！')
  else
    Showmessage('查找失败！');
end;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
with Table1 do
  begin
   IndexName:='ByName';
   SetKey; //进入查询状态
   FieldByName('LastName').AsString:=edit7.text;
   FieldByName('FirstName').AsString:=edit8.text;
  {给查找字段的关键字赋值}
   GotoNearest;
 end;
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
 with Table1 do
  begin
   IndexFieldNames:='EmpNo';//设置索引字段
  If not FindKey([edit9.Text]) then  //查询匹配edit9中内容的记录
   Showmessage('无法找到匹配的记录！');
  end;
end;

procedure TForm1.Button4Click(Sender: TObject);
begin
with Table1 do
  begin
   IndexFieldNames:='EmpNo';//设置索引字段
   FindNearest([edit9.Text]);
  end;
end;

procedure TForm1.Button5Click(Sender: TObject);
var
 A:Boolean;
begin
 A:=Table1.Locate('PhoneExt',edit10.Text,[loPartialKey]);
 if  not A  then
  Showmessage('无法找到匹配的记录！');
end;


procedure TForm1.FormCreate(Sender: TObject);
begin
 try
  Table1.DatabaseName:='DBDEMOS';
  Table1.TableName:='employee.db';
  Table1.Active:=true;
 except
  On E:EdatabaseError do
  ShowMessage(E.Message);
 end;

end;

end.