unit1_login.pas

图书管理系统。可以实现简单的图书管理

unit Unit1_login;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    BitBtn1: TBitBtn;
    BitBtn2: TBitBtn;
    ComboBox1: TComboBox;
    procedure BitBtn1Click(Sender: TObject);
    procedure BitBtn2Click(Sender: TObject);
    procedure FormShow(Sender: TObject);
    //procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

uses Unit_main;

{$R *.dfm}

procedure TForm1.BitBtn1Click(Sender: TObject);
 
begin
datamodule1.adoquery1.Close;
datamodule1.adoquery1.sql.clear;
datamodule1.adoquery1.sql.Add('select 权限 from user1 where 用户名=' +''''+combobox1.text+'''' +' and 密码='+''''+edit1.text+'''');
datamodule1.adoquery1.open;

//while not datamodule1.adoquery1.eof do
 // begin
     //s:=trim(datamodule1.adoquery1.fieldbyname('密码').asstring);
    // if s=trim(edit1.text) then
      if  trim(datamodule1.adoquery1.fieldbyname('权限').asstring)='administor' then
     begin
        showmessage('您的输入完全正确,欢迎使用该系统');
       edit1.Text:='';
       form1.Hide;
       form2.show ;
       form2.n17.Enabled:=true;
       form2.n18.Enabled:=true;
       form2.n19.Enabled:=true;
       form2.n20.Enabled:=true;

     end

  else if trim(datamodule1.adoquery1.fieldbyname('权限').asstring)='user'  then
   begin
   showmessage('您的输入完全正确,欢迎使用该系统');
       edit1.Text:='';
       form1.Hide;
       form2.show ;
       form2.n17.Enabled:=false;
       form2.n18.Enabled:=false;
      // form2.n19.Enabled:=false;
       form2.n20.Enabled:=false;

   end

    else
    begin
       showmessage('对不起,您的输入有误,请重输');
       edit1.Text:='';
       edit1.SetFocus;
    end;
end;




procedure TForm1.BitBtn2Click(Sender: TObject);
begin
  form1.close;
end;

procedure TForm1.FormShow(Sender: TObject);
 
begin
form1.ComboBox1.Clear;
 datamodule1.adoquery1.Close;
 datamodule1.adoquery1.sql.clear;
 datamodule1.adoquery1.sql.Add('select distinct(用户名) from user1');
 datamodule1.adoquery1.open;
 while not datamodule1.adoquery1.eof do
   begin
    combobox1.items.add(datamodule1.adoquery1.Fields[0].asstring);
    datamodule1.adoquery1.Next;
   end;
end;

end.