unit2.~pas

是一个最最傻瓜的链接数据库程序

unit Unit2;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls,DBTables,BDE;

type
  TfrmLogin = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Edit1: TEdit;
    ComboBox1: TComboBox;
    Button1: TButton;
    Button2: TButton;
    procedure Button2Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmLogin: TfrmLogin;

implementation

uses Unit1;
{$R *.dfm}

procedure TfrmLogin.Button2Click(Sender: TObject);
begin
application.Terminate;
end;

procedure TfrmLogin.FormCreate(Sender: TObject);
var
  Query:TQuery;

begin
comboBox1.Clear;
  try
    Query:=TQuery.Create(nil);
    Query.close;
    Query.DatabaseName:='cc';
    Query.SQL.Clear;
    Query.SQL.Add('select userName from operator ');
    Query.Open;
    if Query.RecordCount=0 then
      begin
        MessageDlg('没有可以登录的用户名' ,mtError,[mbok],0);
        Exit;
    end else
      begin
        Query.First;
        while Query.Eof=false do
        begin
          comboBox1.Items.Add(Query.FieldByName('userName').asstring);
          Query.next;
        end;
    end;
      Query.Close;
      Query.Free;
      comboBox1.ItemIndex:=0;
    except MessageDlg('连接数据库出错' ,mtError,[mbok],0);
    end;
end;

procedure TfrmLogin.Button1Click(Sender: TObject);
var
  Query:TQuery;
begin
  try
    Query:=TQuery.Create(nil);
    Query.DatabaseName:='cc';
    Query.SQL.Add('select * from Operator where UserName=:UserName and userpwd=:userpwd');
    Query.Params.ParamByName('UserName').Value:=comboBox1.Text;
    Query.Params.ParamByName('userpwd').Value:=edit1.Text;
    Query.Open;
    if Query.RecordCount=0 then
    begin
      MessageDlg('请输入正确的用户名和密码',mtError,[mbok],0);
      Exit;
    end;
    Query.Close;
    Query.Free;
    frmRoom.Show;
    frmLogin.close;
   except
    MessageDlg('连接数据库出错',mtError,[mbok],0);
   end;


end;

end.