存取。前段时间开发一个运证管理系统就碰到了这样一个问题：要把每个司机的照片

入库。我们可以在主界面放置一个TImage和OpenDialog对话框进行照片的选择，可是

最后怎样将照片存入数据库呢？

下面提供源代码让大家分析（其中删去了一些不相关的东西）：

THuman=class (TComponent)

 Private

  Name:string;

  IDCard:string;

  Sex:Byte;

  Photo:TImage;

  FQuery:TQuery;

  FDatabase:TDatabase;

-          - -

publisned

  property Name:string read FName write FName;

  property IDCard:string read FIDCard write FIDCard;

  property Sex:Byte read FSex write FSex;

  property Photo:TImage read FPhoto write FPhoto;

  property Query:TQuery read FQuery write FQuery;

  property Database:TDatabase read FDatabase write FDatabase;

function THuman.Insert: Boolean;

var

  Sqlstr:string;

  lStream:TMemoryStream;

  lPicture:TJPEGImage;

begin

  lStream:=TMemoryStream.Create;

  lPicture:=TJPEGImage.Create;

// FPhoto为TImage变量，在主界面可以选择一张照片  

 if FPhoto.Picture.Graphic<>nil then

  begin

    lPicture.Assign(FPhoto.Picture.Graphic);

    lPicture.SaveToStream(lStream);

  end;  

  if FDatabase.InTransaction then FDatabase.Commit;

  FDatabase.StartTransaction;

  Query.Sql.text:= 'Insert Into Human(Name,IDCard,Sex,Photo) values(:Name,:IDCard,:Sex,:Photo)’;

  子段前加冒号，动态生成SQL参数,然后给参数赋值：

  Query.ParamByName('Name').asstring:=’张家恶少’;

  Query.ParamByName('IDCard').asstring:=Something;

  Query.ParamByName('Sex').asstring:=Something;

  Query.ParamByName('Photo').LoadFromStream(lStream,ftBlob);

  try

    Query.Prepare;

    Query.execSQL;

    Query.Close;

    FreeAndNil(lStream);

    FreeAndNil(lPicture);

   Result:=True;

    FDatabase.Commit;

  except

    FDatabase.Rollback;

    Query.Close;

    FreeAndNil(lStream);

    FreeAndNil(lPicture);

    Result:=False;

  end;

  最后要主要释放动态生成的LStream 和 LPicture

E_mail: zhangyi1980912@sina.com  QQ: 8133413  张家恶少