unit10.pas

本例是用delphi开发的学生与课程信息管理系统

unit Unit10;

interface

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

type
  TFormlogin = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Editid: TEdit;
    Editpassword: TEdit;
    Button1: TButton;
    ADOQuerylogin: TADOQuery;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Formlogin: TFormlogin;

implementation

uses Unit1;

{$R *.dfm}

procedure TFormlogin.Button1Click(Sender: TObject);
var
  id,password,temp:string;
begin
  id:=trim(editid.Text);
  password:=trim(editpassword.Text);
  adoquerylogin.Close;
  adoquerylogin.SQL.Clear;
  adoquerylogin.SQL.text:='select right1 from login where id='''+id+''' and password='''+password+'''';
  adoquerylogin.Open;
  temp:=adoquerylogin.fieldbyname('right1').asstring;

  if temp='1' then
    begin
     formmain.Show;
     formlogin.Hide;  
    end
  else if temp='2' then
    begin
      formmain.Nstu.Visible:=false;
      formmain.Ncou.Visible:=false;
      formmain.Show;
      formlogin.Hide;
    end
  else if temp='' then

      showmessage('您输入的用户名或密码错误！');
end;

end.