照片读取问题(100分)

我用下列程序，把程序存储到SQL SERVER数据库，但总出现Invalid class typecast提示。
FieldByName('FILENAME').AsString:=ExtractFileName(OpenPictureDialog1.FileName);
Stream:=TmemoryStream.Create();
Stream.LoadFromFile(OpenPictureDialog1.FileName);
Tblobfield(FieldByName('ZP')).LoadFromStream(Stream);
adotable1.Post;

ZP要用Image字段类型

FieldByName('FILENAME').AsString:=ExtractFileName(OpenPictureDialog1.FileName);
Stream:=TmemoryStream.Create();
Stream.LoadFromFile(OpenPictureDialog1.FileName);
Stream.Position := 0; //这句，注意指针要回到头部
Tblobfield(FieldByName('ZP')).LoadFromStream(Stream);
adotable1.Post;

procedure cunpic(const Field: TField; const Bmp: TBitmap);
var
JPEGImage: TJpegImage;
Stream: TMemoryStream;
begin
if (not Bmp.Empty) then
begin
JPEGImage := TJpegImage.Create;
Stream := TMemoryStream.Create;
try
JPEGImage.Assign(Bmp);
Stream.Clear;
JPEGImage.SaveToStream(Stream);
TBlobField(Field).LoadFromStream(Stream);
finally
JPEGImage.Free;
Stream.Free;
end;
end;
end;

使用
cunpic(FieldByName('ZP'), ABitmap);

这几天一直上不了此网站，所以....把照片的数据类型改为IMAGE以后存不了记录的问题就解决啦。数据库为ACCESS时，照片的数据类型为BINARY也不出现异常。