[Mono-dev] Sybase ASA Odbc, timestamp, fractional seconds, possible bug in mono Odbc stack?

[Mads Bondo Dydensborg]

tirsdag 24 april 2007 08:36 skrev Mads Bondo Dydensborg:
> Hi there

Hi again.

Just a repost - does nobody know anything about these issues?

Regards,

Mads

> 
> I am using Linux/Mono to access a Sybase ASA server (on Windows), using 
> Unixodbc (and possibly FreeTDS - I am actually not quite sure).
> 
> Most things appear to work fine, however, when retrieving 
DateTimes/Timestamps 
> from the sybase server, it seems that it returns the fractional value of a 
> second, as _billonths_ of a second. Mono appears to expect this in 
> milliseconds: 
> 
> ENTER: System.DateTime:.ctor (int,int,int,int,int,int,int)(value:0xbf8b53b0, 
> 2007, 4
> , 17, 14, 10, 50, 340000000, )
> . ENTER: System.DateTime:DaysInMonth (int,int)(2007, 4, )
> . . ENTER: System.DateTime:IsLeapYear (int)(2007, )
> . . LEAVE: System.DateTime:IsLeapYear (int)FALSE
> . LEAVE: System.DateTime:DaysInMonth (int,int)result=30
> EXCEPTION handling: ArgumentOutOfRangeException
> 
> The value 340000000 should be in milliseconds (says DateTime constructor), 
but 
> apperantly is in billionths of a second (nanoseconds, says ODBC).
> 
> Looking at OdbcDataReader.GetValue, I find the following code:
> 
> case OdbcType.Timestamp:
> case OdbcType.DateTime:
> case OdbcType.Date:
> case OdbcType.Time:
>     OdbcTimestamp ts_data = new OdbcTimestamp();
>     ret = libodbc.SQLGetData (hstmt, ColIndex, col.SqlCType, ref ts_data, 0, 
> ref outsize);
>     if (outsize!=-1) // This means SQL_NULL_DATA
>       DataValue = new 
> DateTime(ts_data.year,ts_data.month,ts_data.day,ts_data.hour, 
> ts_data.minute,ts_data.second,Convert.ToInt32(ts_data.fraction));
>  break;
> 
> OdbcTimestamp.fraction is declared as a long. SQLGetData is an extern 
method - 
> looks like it is just supposed to fill in the binary values? I find it a bit 
> puzzling, perhaps even suspiciuos, that ts_data.fraction is converted to an 
> int 32 from a long in the call to DateTime - disregarding (perhaps?) the 
> scale of the fraction?
> 
> I am a bit confused about this. Before looking into it further, I would 
> appreciate a comment on wheter this could potentially be a bug in the Mono 
> ODBC stack? Also, where values are "set", that is, if wanting to update a 
> timestamp from mono - where the conversion takes place (there are quite many 
> Odbc related files :-).
> 
> The same code runs without problems under Windows/MS. Of course, that is not 
> to say it is correct, only that the data returned is as expected.
> 
> Regards,
> 
> Mads
> 
> -- 
> Med venlig hilsen/Regards
> 
> Systemudvikler/Systemsdeveloper cand.scient.dat, Ph.d., Mads Bondo 
Dydensborg
> Dansk BiblioteksCenter A/S, Tempovej 7-11, 2750 Ballerup, Tlf. +45 44 86 77 
34
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> 
> 

-- 
Med venlig hilsen/Regards

Systemudvikler/Systemsdeveloper cand.scient.dat, Ph.d., Mads Bondo Dydensborg
Dansk BiblioteksCenter A/S, Tempovej 7-11, 2750 Ballerup, Tlf. +45 44 86 77 34