Malformed blobs (jpg) - zeos + firebird
lazarus / 16-Databases

----------------------------------------------------------------------
tomek1 · 2019-01-28 12:57

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 · 2019-01-28 13:18

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

----------------------------------------------------------------------
rvk · 2019-01-28 13:36

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

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i TBlobField(
ZQuery1.ParamByName('PLATE_PIC')).LoadFromFile(ExtractFilePath(ParamSt
r(0)) + 'test.jpg');ZQuery1.ExecSQL;

----------------------------------------------------------------------
tomek1 · 2019-01-28 14:31

Quote from: GetMem on January 28, 2019, 02:18:13 pmTry to set
Stream.Position to 0 after Stream.LoadFromFile.

It doesn't fix the problem.

Quote from: rvk on January 28, 2019, 02:36:31 pmYou 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 · 2019-01-28 14:47

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 · 2019-01-28 15:26

I used the following code for years and it works fine, you have to
adapt it to your needs though:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i var  St:
TStream;begin  SQLQuery1.Edit;  St :=
SQLQuery1.CreateBlobStream(SQLQuery1.FieldByName('PICTURE'), bmWrite);
//PICTURE --> BLOB SUB_TYPE 0 SEGMENT SIZE 80(binary)  try   
Image1.Picture.SaveToStream(St);    SQLQuery1.ApplyUpdates;   
SQLTransaction.CommitRetaining;  finally    St.Free;  end;end;

----------------------------------------------------------------------
tomek1 · 2019-01-29 09:28

Quote from: rvk on January 28, 2019, 03:47:50 pmLooking 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 · 2019-01-29 09:39

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 · 2019-01-30 11:24

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