unit USale;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Buttons,IdGlobal;

type
  TForm6 = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Edit1: TEdit;
    Edit2: TEdit;
    Edit3: TEdit;
    Button1: TButton;
    Button2: TButton;
    SpeedButton1: TSpeedButton;
    procedure Button1Click(Sender: TObject);
    procedure SpeedButton1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form6: TForm6;
  AmountLeft:Integer;

implementation

uses USelect, Udm;

{$R *.dfm}

procedure TForm6.Button1Click(Sender: TObject);
var
  strSql:String;
  nDiscount,nAmount:Integer;
begin
  //是否已經(jīng)選擇了某一書本
  if Edit1.Text = '' then
  begin
    Application.MessageBox('請先選擇書籍！','系統(tǒng)提示');
    Exit;
  end;

  nDiscount :=StrToIntDef(Trim(Edit2.Text),-1);
  if (nDiscount>100) or (nDiscount<0) then
  begin
    Application.MessageBox('輸入的折扣有錯(cuò)！','系統(tǒng)提示');
    Exit;
  end;

  nAmount :=StrToIntDef(Edit3.Text,-1);
  if (nAmount<1) then
  begin
    Application.MessageBox('輸入數(shù)量出錯(cuò)！','系統(tǒng)提示');
    Exit;
  end;
  if nAmount>AmountLeft then
  begin
    Application.MessageBox('庫存不夠！','系統(tǒng)提示');
    Exit;
  end;

  //保存數(shù)據(jù)
  Dm.ConnBookstore.BeginTrans;
  try
    strSql :='Insert SalesList (Discount,Amount,ISBN) Values('
          +Trim(Edit2.Text)+','+Trim(Edit3.Text)+','''
          +Trim(Edit1.Text)+''')';
    Dm.ConnBookstore.Execute(strSql);
    strSql :='Update book Set AmountLeft='+IntToStr(AmountLeft-nAmount)
          +'Where ISBN='''+Trim(Edit1.Text)+'''';
    Dm.ConnBookstore.Execute(strSql);
    Dm.ConnBookstore.CommitTrans;
    Application.MessageBox('操作成功！','系統(tǒng)提示');
    Edit1.Text :='';
    Edit2.Text :='';
    Edit3.Text :='';
  except
    Dm.ConnBookstore.RollbackTrans; 
  end;
  
end;

procedure TForm6.SpeedButton1Click(Sender: TObject);
begin
  Dm.TblBook.Requery;
  if Form7.ShowModal=mrOK then
  begin
    Edit1.Text :=Dm.TblBook.FieldByName('ISBN').AsString;
    AmountLeft :=Dm.TblBook.FieldByName('AmountLeft').AsInteger;
  end;
end;

procedure TForm6.Button2Click(Sender: TObject);
begin
  Close;
end;

end.