unit7.pas

简单的一个computer系统

unit Unit7;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Grids, DBGrids,Unit3, StdCtrls, ExtCtrls;

type
  TForm7 = class(TForm)
    DBGrid1: TDBGrid;
    Button1: TButton;
    Button2: TButton;
    Button4: TButton;
    Button5: TButton;
    GroupBox1: TGroupBox;
    CheckBox1: TCheckBox;
    CheckBox2: TCheckBox;
    CheckBox3: TCheckBox;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Edit1: TEdit;
    Edit2: TEdit;
    Edit3: TEdit;
    Button3: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);



  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form7: TForm7;

implementation

{$R *.dfm}

procedure TForm7.Button1Click(Sender: TObject);   //连接
begin
 dm.ADOQuery2.Close;
  dm.ADOQuery2.SQL.Clear;
  dm.ADOQuery2.SQL.Add('select * from xsb');
  dm.ADOQuery2.Open;

 self.DBGrid1.DataSource:=dm.DataSource2;
end;

procedure TForm7.Button2Click(Sender: TObject);         //查询
var
sqlstr:string;
begin

 if (self.CheckBox1.Checked=false) and
     (self.CheckBox2.Checked=false) and
     (self.CheckBox3.Checked=false) then
    sqlstr:=''
  else
  begin
    sqlstr:='where  ';
    if self.CheckBox1.Checked=true then
      sqlstr:=sqlstr+'电脑编号='''+trim(self.Edit1.Text)+''' and  ';
    if self.CheckBox1.Checked=true then
      sqlstr:=sqlstr+'销售商编号='''+self.Edit2.Text+''' and  ';
    if self.CheckBox1.Checked=true then
      sqlstr:=sqlstr+'价格='''+self.Edit3.Text+''' and  ';
      sqlstr:=sqlstr+'1=1';
  end;

  dm.ADOQuery2.Close;
  dm.ADOQuery2.SQL.Text:='select * from xsb '+sqlstr;
  dm.ADOQuery2.Open;

  self.DBGrid1.DataSource:=dm.DataSource2;
end;

procedure TForm7.Button3Click(Sender: TObject);     //增加
begin
if self.Edit1.Text='' then
begin
  showmessage('为空');
  exit;
end;
  dm.ADOQuery2.Close;
  dm.ADOQuery2.SQL.Text:='select * from xsb where 电脑编号='+self.Edit1.Text;
  dm.ADOQuery2.Open;
  if not(dm.ADOQuery2.IsEmpty) then
begin
  showmessage('用户已存在');
  exit;
end;
  dm.ADOQuery2.Close;
  dm.ADOQuery2.SQL.Text:='insert into xsb (电脑编号,销售商编号)values('+self.Edit1.Text+','''+self.Edit2.Text+''')';
  dm.ADOQuery2.ExecSQL;
  dm.ADOQuery2.Close;
  dm.ADOQuery2.SQL.Text:='select * from xsb';

  self.DBGrid1.DataSource:=dm.DataSource2;
end;

procedure TForm7.Button4Click(Sender: TObject);
begin                                                    // 删除
dm.ADOQuery2.Close;
  dm.ADOQuery2.SQL.Text:='delete from  xsb where 电脑编号='+self.Edit1.Text;
  dm.ADOQuery2.ExecSQL;
  dm.ADOQuery2.Close;
  dm.ADOQuery2.SQL.Text:='select * from xsb ';
  dm.ADOQuery2.Open;
  self.DBGrid1.DataSource:=dm.DataSource2;
end;

procedure TForm7.Button5Click(Sender: TObject);
begin                                                      //修改
try
  dm.ADOConnection1.Open();
  dm.ADOConnection1.BeginTrans;
  dm.ADOQuery2.Close;
  dm.ADOQuery2.SQL.Text:='update xsb set 电脑编号=电脑编号+1 where 销售商编号='+self.Edit2.Text;
  dm.ADOQuery2.ExecSQL;

  dm.ADOConnection1.CommitTrans;
  showmessage('成功');
  except
  dm.ADOConnection1.RollbackTrans;
  showmessage('失败');
 end
end;

end.