插入修改 保存图象
bmTemp:=TBitmap.Create;
ms:=TMemoryStream.Create;
try
    qryFace.Close;
    qryFace.SQL.Clear;
    qryFace.SQL.Add('update video_face_image set face_image2=:face_image2');
    qryFace.SQL.Add(Format('where event_id=%d',[qryPrepare.FieldByName('event_id').AsInteger]));
    bmTemp.LoadFromFile('c:\face2.bmp');
    bmTemp.SaveToStream(ms);                      
    qryFace.Parameters.ParamByName('face_image2').LoadFromStream(ms,ftBlob);
finally
    ms.Free;
    bmTemp.Free;
end;

如何在Image组件中显示
bmTemp:=TBitmap.Create;
ms:=TMemoryStream.Create;
try
    TBlobField(qryFace.FieldByName('face_image1')).SaveToStream(ms);
    ms.Position:=0;  //最最重要的一点
    bmTemp.LoadFromStream(ms);
    imgFace1.Picture.Bitmap:=bmTemp;
finally
    ms.Free;
    bmTemp.Free;
end;