Re: SQL_ATTR_TRACE option doesn't work

On 07/04/2010 6:32 PM, James K. Lowden wrote:
> [email protected] wrote:
>    
>> I'm calling this API:
>> ::SQLSetConnectAttr(
>>                                    hdbc,
>>                                    SQL_ATTR_TRACE,
>>                                    (SQLPOINTER)sitrace,
>>                                    0 );
>>
>> where sitrace is one of SQL_OPT_TRACE_ON or SQL_OPT_TRACE_OFF
>> and get this error back:
>>
>> HY092, Native error: 0, Msg: [FreeTDS][SQL Server]Invalid option;
>>
>> I checked the source code in odbc.c and found that unless TDS_NO_DM is
>> defined the driver doesn't understand this option.
>>      
> http://msdn.microsoft.com/en-us/library/ms713605(VS.85).aspx
>
> It's normally a DM feature:
>
> 	"An SQLUINTEGER value telling the Driver Manager whether to perform
> tracing:
>
> SQL_OPT_TRACE_OFF = Tracing off (the default)
> SQL_OPT_TRACE_ON = Tracing on
>
> When tracing is on, the Driver Manager writes each ODBC function call to
> the trace file."
>
> It's not supported by the driver unless there's no DM present.  If you
> removed the preprocessor guards, I would think you'd hit some kind of
> conflict.
>
> HTH.
>
> --jkl
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>    
But it works when I use it before SQLConnect. I think the reason is that 
after SQLConnect the DM loads FreeTDS library and then some calls to 
SQLSetConnectAttr are passed through to the driver including 
SQL_ATTR_TRACE, which I think it shouldn't do.
So it looks like a bug in DM, not in FreeTDS.
On Windows it works fine because of different DM.

Mikhail