[Mono-dev] Sybase ASA Odbc, timestamp, fractional seconds, possible bug in mono Odbc stack?
Mads Bondo Dydensborg
mbd at dbc.dk
Tue Apr 24 02:36:43 EDT 2007
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
ENTER: System.DateTime:.ctor (int,int,int,int,int,int,int)(value:0xbf8b53b0,
, 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:
OdbcTimestamp ts_data = new OdbcTimestamp();
ret = libodbc.SQLGetData (hstmt, ColIndex, col.SqlCType, ref ts_data, 0,
if (outsize!=-1) // This means SQL_NULL_DATA
DataValue = new
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.
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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