cw_mm.pas

结于初学者来说这对数据库是一个很好的例子

unit cw_mm;

interface

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

type
  TForm45 = class(TForm)
    Label1: TLabel;
    Panel1: TPanel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Label5: TLabel;
    Label6: TLabel;
    Button1: TButton;
    Button2: TButton;
    oldpass: TEdit;
    newpass: TEdit;
    newpass2: TEdit;
    Q_pass: TQuery;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form45: TForm45;

implementation

{$R *.dfm}

procedure TForm45.Button1Click(Sender: TObject);
begin
 if trim(newpass.Text)=trim(newpass2.Text) then
 begin
 Q_pass.Active:=False;
 Q_pass.SQL.Clear;
 Q_pass.SQL.Add('select * from manager where name='''+label6.Caption+'''');
 Q_pass.Open;
  if Q_pass.FieldByName('pass').AsString=trim(oldpass.Text) then
  begin
   Q_pass.Edit;
   Q_pass['pass']:=trim(newpass.Text);
   Q_pass.Post;
   Q_pass.Close;
   MessageDlg('密码更改成功！',mtConfirmation,[mbok],0);
   oldpass.Clear;
   newpass.Clear;
   newpass2.Clear;
   close;
  end
  else
  begin
       MessageDlg('您输入的原密码不正确，请重新输入！',mtError,[mbok],0);
       oldpass.SetFocus;
  end;
 end
 else
 begin
       MessageDlg('您两次输入的新密码不一致，请重新输入！',mtError,[mbok],0);
       newpass.SetFocus;
 end;

end;

end.