存取。前段時間開發一個運證管理系統就碰到了這樣一個問題：要把每個司機的照片

入庫。我們可以在主界面放置一個TImage和OpenDialog對話框進行照片的選擇，可是

最后怎樣將照片存入數據庫呢？

下面提供源代碼讓大家分析（其中刪去了一些不相關的東西）：

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為TImage變量，在主界面可以選擇一張照片  

 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)’;

  子段前加冒號，動態生成SQL參數,然后給參數賦值：

  Query.ParamByName('Name').asstring:=’張家惡少’;

  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;

  最后要主要釋放動態生成的LStream 和 LPicture

E_mail: zhangyi1980912@sina.com  QQ: 8133413  張家惡少