Display VARBINARY(MAX) in FreeTDS

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-We made two new drivers: odbc(raw and unicode version) and oledb
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-extended error infos of Firebird
-performance ups are still in queue
In future some more feature will arrive, so stay tuned and don't hassitate to help
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brick08
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Display VARBINARY(MAX) in FreeTDS

Post by brick08 »

Hi,
when displaying a column with a type VARBINARY(MAX) in MSSQL Server, an error occurs in ZDbcCache.pas:

Code: Select all

    stBytes: if (FColumnLengths[ColumnIndex] <= 0) or (FColumnLengths[ColumnIndex] = MaxInt)
      then Result := TZRowAccessorBytesLob.CreateWithDataAddess(PZVarLenDataRef(TempBlob), zCP_Binary, ConSettings, FOpenLobStreams)
      else goto Fail; 
because the value of FColumnLengths[ColumnIndex] is 1073741823.
It seems to me that you need to add a check for this value in ZDbcResultSetMetadata.pas:

Code: Select all

      if (ColumnType = stBytes) and ((Precision = 2147483647) or (Precision = 1073741823)) then begin 
        Precision := 0;
        Scale := 0;
      end; 
I added screenshot of tdslog with size of this type
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marsupilami
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Re: Display VARBINARY(MAX) in FreeTDS

Post by marsupilami »

Hello brick08,

I changed Zeos trunk and Zoes 8 accordingly. Could you please test if it works?

Best regards,

Jan
brick08
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Re: Display VARBINARY(MAX) in FreeTDS

Post by brick08 »

marsupilami wrote: 28.03.2023, 14:57 Could you please test if it works?
Yes, now its ok, thanks.

I'll add more so I don't create a new topic.
When ZConnection.Reconnect or after lost connection I do ZQuery.Close and ZQuery.Open. And If query has parameters, then an error occurs, because query text is garbled. I think that TZAbstractDBLibStatement = class(TZRawParamDetectPreparedStatement) does not follow the procedure TZRawParamDetectPreparedStatement.GetRawEncodedSQL(const SQL: SQLString): RawByteString when Query.Open again. So TZQuestionMarkBindList(BindList)[InParamCount].QMarkPosition value don't updated. And in module ZDbcDbLibStatement.pas code SQLWriter.AddText(P+LastPos, QMarkBindValue.QMarkPosition - LastPos, Result) add wrong string because QMarkBindValue.QMarkPosition value is 0.
Code forexample, use mssql protocol type:

Code: Select all

ZQuery.Close;
    ZQuery.SQL.Text := 'select id from tmp_table where id = :id';
    ZQuery.ParamByName('id').AsInteger := 1;
    ZQuery.Open;
    ZConnection.Reconnect;
    ZQuery.Close;
    ZQuery.Open;
P.S.
And I want to copy ZMemTable without data. i suggest to add parameter to copy data. Attached patch for example. Thanks.
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marsupilami
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Re: Display VARBINARY(MAX) in FreeTDS

Post by marsupilami »

brick08 wrote: 29.03.2023, 08:19 When ZConnection.Reconnect or after lost connection I do ZQuery.Close and ZQuery.Open. And If query has parameters, then an error occurs, because query text is garbled. I think that TZAbstractDBLibStatement = class(TZRawParamDetectPreparedStatement) does not follow the procedure TZRawParamDetectPreparedStatement.GetRawEncodedSQL(const SQL: SQLString): RawByteString when Query.Open again. So TZQuestionMarkBindList(BindList)[InParamCount].QMarkPosition value don't updated. And in module ZDbcDbLibStatement.pas code SQLWriter.AddText(P+LastPos, QMarkBindValue.QMarkPosition - LastPos, Result) add wrong string because QMarkBindValue.QMarkPosition value is 0.
Code forexample, use mssql protocol type:

Code: Select all

ZQuery.Close;
    ZQuery.SQL.Text := 'select id from tmp_table where id = :id';
    ZQuery.ParamByName('id').AsInteger := 1;
    ZQuery.Open;
    ZConnection.Reconnect;
    ZQuery.Close;
    ZQuery.Open;
I think we fixed that one. Could you please check if the current revision of Zeos 7.3 from SVN works? Github should be updated tomorrow.
marsupilami
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Re: Display VARBINARY(MAX) in FreeTDS

Post by marsupilami »

brick08 wrote: 29.03.2023, 08:19 And I want to copy ZMemTable without data. i suggest to add parameter to copy data. Attached patch for example. Thanks.
I applied the patch. Thank you :)
brick08
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Re: Display VARBINARY(MAX) in FreeTDS

Post by brick08 »

marsupilami wrote: 04.04.2023, 11:50 I think we fixed that one. Could you please check if the current revision of Zeos 7.3 from SVN works?
Now, its work fine. Thanks. :wink:
marsupilami wrote: 04.04.2023, 12:05 I applied the patch. Thank you :)
Thank you too :)
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