Malformed blobs (jpg) - zeos + firebird

[tomek1]

Hi
I'm inserting jpg's to blob field, everything seems to work properly, but blob content is malformed. Here's the sample code:

Code: [Select]

  ZQuery1.SQL.Text := 'insert into PLATES (ID,'
                    + '                    PLATE_PIC)'
                    + 'values (gen_id(GEN_PLATES, 1),'
                    + '        :PLATE_PIC)';

  Stream := TMemoryStream.Create;
  try
    Stream.LoadFromFile(ExtractFilePath(ParamStr(0)) + 'test.jpg');
    ZQuery1.ParamByName('PLATE_PIC').LoadFromStream(Stream, ftBlob);
    //ZQuery1.ParamByName('PLATE_PIC').SetBlobData(Stream.Memory, Stream.Size);
    ZQuery1.ExecSQL;
  finally
    Stream.Free;
  end;

Below printscreens with hex content of the file, and blob in db. Content differs more, not only first 4 bytes.
Firebird 2.5.2, charset utf8, PLATE_PIC is blob subtype binary.

Regards, Tomek

[balazsszekely]

Try to set Stream.Position to 0 after Stream.LoadFromFile.

[rvk]

You might even be able to just use LoadFromFile() directly.

Code: Pascal  [Select][+][-]

1. TBlobField(ZQuery1.ParamByName('PLATE_PIC')).LoadFromFile(ExtractFilePath(ParamStr(0)) + 'test.jpg');
2. ZQuery1.ExecSQL;

[tomek1]

Try to set Stream.Position to 0 after Stream.LoadFromFile.

It doesn't fix the problem.

You might even be able to just use LoadFromFile() directly.

The code above is actually a test case, real app gets the the pic in stream.

Regards, Tomek

[rvk]

Looking at those "?" I expect every $ff and subsequent character is converted (because of UTF-8).
That shouldn't happen but I'm not sure what happens in the parameters in Zeoslib.

Can you check what the type is of the parameter ZQuery1.ParamByName('PLATE_PIC').DataType?
It should be ftBlob. Otherwise you could clear and create the parameters by hand.

I also never worked with parameters to directly insert a blob.
You could try to do a SELECT ID, PLATE_PIC FROM PLATES and do a ZQuery1.Insert and fill in the fields at that point.

[balazsszekely]

I used the following code for years and it works fine, you have to adapt it to your needs though:

Code: Pascal  [Select][+][-]

1. var
2.   St: TStream;
3. begin
4.   SQLQuery1.Edit;
5.   St := SQLQuery1.CreateBlobStream(SQLQuery1.FieldByName('PICTURE'), bmWrite); //PICTURE --> BLOB SUB_TYPE 0 SEGMENT SIZE 80(binary)
6.   try
7.     Image1.Picture.SaveToStream(St);
8.     SQLQuery1.ApplyUpdates;
9.     SQLTransaction.CommitRetaining;
10.   finally
11.     St.Free;
12.   end;
13. end;    

[tomek1]

Looking at those "?" I expect every $ff and subsequent character is converted (because of UTF-8).
That shouldn't happen but I'm not sure what happens in the parameters in Zeoslib.

Can you check what the type is of the parameter ZQuery1.ParamByName('PLATE_PIC').DataType?
It should be ftBlob. Otherwise you could clear and create the parameters by hand.

I also never worked with parameters to directly insert a blob.
You could try to do a SELECT ID, PLATE_PIC FROM PLATES and do a ZQuery1.Insert and fill in the fields at that point.

DataType of param is fbBlob.

Select/Insert/FieldByName isn't preferred nor optimal approach, but it works! (the ZQuery1 's only purpose is batch insert).

Thank you both for help.

Regards, Tomek

[EgonHugeist]

Hi tomek1,

Which version did you use? There was a regression(Buf overrun of 4Bytes with the Currency values) in the SVN version, i fixed yesterday evening.
If you don't use SVN than please open a ticked in the Zeos bugtracker https://sourceforge.net/p/zeoslib/tickets/
else update from SVN.

[tomek1]

Hi
I was using 7.2.1-rc.
I've tested 7.2.4-stable - problem still remains.
Latest version (snapshot) solves the problem!

Thx for help.

Regards, Tomek