unit Unit19;

interface
   {11111111111111111111111111111}

        {用戶管理窗體}

   {11111111111111111111111111111}
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs,unit2, DB, ADODB, XPMenu, StdCtrls, ComCtrls;

type
  TForm19 = class(TForm)
    PageControl1: TPageControl;
    TabSheet1: TTabSheet;
    TabSheet2: TTabSheet;
    TabSheet3: TTabSheet;
    Edit1: TEdit;
    Edit2: TEdit;
    Button1: TButton;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Edit3: TEdit;
    XPMenu1: TXPMenu;
    db4: TADOQuery;
    Label4: TLabel;
    Edit4: TEdit;
    Label5: TLabel;
    Edit5: TEdit;
    Button2: TButton;
    Label6: TLabel;
    Edit6: TEdit;
    Label7: TLabel;
    Edit7: TEdit;
    Label8: TLabel;
    Edit8: TEdit;
    Label9: TLabel;
    Edit9: TEdit;
    Button3: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form19: TForm19;

implementation

{$R *.dfm}

procedure TForm19.Button1Click(Sender: TObject);
begin
db4.Close;
db4.SQL.Clear;
db4.SQL.Add('select * from 用戶 where 用戶名=');
db4.SQL.Add(''''+edit1.Text+'''');
db4.Open;
if not db4.IsEmpty then
begin
  showmessage('該用戶已經存在!請另選取一個用戶名');
  exit;
end;
if edit2.text<>edit3.Text then
begin
  showmessage('兩次密碼不一樣,請重新確定!');
  exit;
end;
db4.Close;
db4.SQL.Clear;
db4.SQL.Add('insert into 用戶 (用戶名,密碼) ');
db4.SQL.add('values('''+edit1.Text+''',');
db4.SQL.add(''''+edit2.Text+''')');
db4.execsql;
showmessage('用戶添加成功');
edit1.Clear;
edit2.Clear;
edit3.Clear;
end;

procedure TForm19.Button2Click(Sender: TObject);
begin
db4.Close;
db4.SQL.Clear;
db4.SQL.Add('select * from 用戶  ') ;
db4.sql.Add(format('where 用戶名=''%s'' and 密碼=''%s''',[edit4.text,edit5.text]));
db4.Open;
if db4.IsEmpty then
begin
showmessage( '對不起,輸入不正確.你不能刪除');
exit;
end;
db4.Delete;
showmessage('該用戶已經刪除');
edit4.Clear;
edit5.Clear;
end;

procedure TForm19.Button3Click(Sender: TObject);
begin
db4.Close;
db4.SQL.Clear;
db4.SQL.Add('select * from 用戶  ') ;
db4.sql.Add(format('where 用戶名=''%s'' and 密碼=''%s''',[edit6.text,edit7.text]));
db4.Open;
if db4.IsEmpty then begin
showmessage('沒有該用戶或者密碼有誤,請核對!');
exit;
end;
if edit9.text<>edit8.Text then
begin
showmessage('兩次輸入的密碼不一致');
exit;
end;
db4.Delete;
db4.Edit;
db4.FieldValues['用戶名']:=edit6.Text;
db4.FieldValues['密碼']:=edit8.Text;
db4.Post;
showmessage('用戶修改完成,請記住新信息!');
edit6.Clear;
edit7.Clear;
edit8.Clear;
edit9.Clear;
end;

end.