give_up.~pas

来自「该是一个比较好的图书馆系统,是现在大学生软件课程设计的好模板」· ~PAS 代码 · 共 75 行

unit give_up;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Buttons, ADODB, DB, jpeg, ExtCtrls;

type
  Tgiveup = class(TForm)
    Label1: TLabel;
    Edit1: TEdit;
    BitBtn1: TBitBtn;
    ADOQuery1: TADOQuery;
    ADOCommand1: TADOCommand;
    Image1: TImage;
    BitBtn2: TBitBtn;
    procedure BitBtn1Click(Sender: TObject);
    procedure BitBtn2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  giveup: Tgiveup;

implementation

{$R *.dfm}

procedure Tgiveup.BitBtn1Click(Sender: TObject);
begin
 if Edit1.Text<>'' then
 begin
 ADOQuery1.Close;
 ADOQuery1.SQL.Clear;
 ADOQuery1.SQL.Text:='select * from [User] where StuID='''+Edit1.Text+'''';
 ADOQuery1.Open;
 if ADOQuery1.FieldByName('StuID').AsString<>'' then
 begin
   ADOQuery1.Close;
   ADOQuery1.SQL.Clear;
   ADOQuery1.SQL.Text:='select * from Borrow where UserID='''+Edit1.Text+'''';
   ADOQuery1.Open;
   if ADOQuery1.FieldByName('Symbol').AsInteger=0 then
   begin
    showmessage('该读者有书未还，不能注销！');
    end
    else
    begin
   adocommand1.CommandText:='delete from [User] where StuID='''+Edit1.Text+'''';
   adocommand1.Execute;
   adocommand1.CommandText:='delete from login_User where UserID='''+Edit1.Text+'''';
   adocommand1.Execute;
   adocommand1.CommandText:='delete from Borrow where UserID='''+Edit1.Text+'''';
   adocommand1.Execute;
   showmessage('注销成功！');
   end
 end
 else
 showmessage('该用户不存在');
 end
 else
 showmessage('用户帐号不能为空！');
end;

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

end.