Delphi ADO访问数据库

unit ado;

interface

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

type
TfrmMain = class(TForm)
edt1: TEdit;
edt2: TEdit;
edt3: TEdit;
edt4: TEdit;
btnTest: TButton;
lbl1: TLabel;
lbl2: TLabel;
lbl3: TLabel;
lbl4: TLabel;
dbgrd: TDBGrid;
dsDataSource: TDataSource;
conADOConnection: TADOConnection;
qryADOQuery: TADOQuery;
dsADODataSet: TADODataSet;
procedure OnFormCreate(Sender: TObject);
procedure btnTestClick(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
frmMain: TfrmMain;

implementation

{$R *.dfm}

procedure TfrmMain.btnTestClick(Sender: TObject);
var i1,i2,i3,i4:Integer;
begin
i1 :=0;
i2 :=0;
i3 :=0;
i4 :=0;

with qryADOQuery do
begin
Close;
SQL.Text :='select FSalage from Person';
Open;;
end;
while not qryADOQuery.Eof do
begin
case qryADOQuery.FieldByName('FSalage').AsInteger of
0..999:Inc(i1);
1000..1999:Inc(i2);
2000..2999:inc(i3);
else
inc(i4);
end;
qryADOQuery.Next;
end;
edt1.Text := IntToStr(i1);
edt2.Text := IntToStr(i2);
edt3.Text := IntToStr(i3);
edt4.Text := IntToStr(i4);
end;

procedure TfrmMain.OnFormCreate(Sender: TObject);
begin
conADOConnection.ConnectionString :='Provider=Microsoft.Jet.OLEDB.4.0;Data Source='+extractfilepath(Application.ExeName)+'Test.mdb;Persist Security Info=False';
dsADODataSet.Active := False;
dsADODataSet.Active := True;
end;

end.