Informix ODBC Query Appends Time on a date field - asp.net

Question

I have a .aspx page that has query to and informix database. This query is done via an odbc connection and is put into a datatable. Then this datatable is used as the datasource for a radio button group.
My problem is that for whatever reason the time is being appended to the radio button as "12:00:00 AM". This is odd because the informix field is a date field that does not include the time. If I were to run the query outside of the webpage it returns it without the time... "2012-06-15"
So in summary... what I am getting is: "6/15/2012 12:00:00 AM" and what I want is "06/15/2012"
The query is as follows:
"select DATE(attend_date) as attend_date from soar_major_table where major =? and active<>'N'"
The code that creates the datatable:
string connString;
connString = ConfigurationManager.ConnectionStrings [ "ERP" ].ConnectionString;
OdbcConnection conn = new OdbcConnection ( );
conn.ConnectionString = connString;
string sql = "select DATE(attend_date) as attend_date from soar_major_table where major =? and active<>'N' ";
OdbcCommand command = new OdbcCommand ( );
command.CommandText = sql;
command.Parameters.Add ( new OdbcParameter ( "major", major ) );
command.Connection = conn;
DataTable dt = new DataTable ( );
OdbcDataAdapter dataAdapter = new OdbcDataAdapter ( );
dataAdapter.SelectCommand = command;
try
{
conn.Open ( );
dataAdapter.Fill ( dt );
}
finally
{
if ( conn != null && conn.State == ConnectionState.Open )
{
command.Dispose ( );
dataAdapter.Dispose ( );
conn.Close ( );
}
}
return dt;
And lastly the population of the radio btn group:
if ( dt.Rows.Count > 0 )
{
rdoDate.DataSource = dt;
rdoDate.DataTextField = "attend_date";
rdoDate.DataValueField = "attend_date";
rdoDate.DataBind ( );
}

Answer 1

The problem is upstream of the Informix data server, I believe.
When you execute:
SELECT DATE(attend_date) ...
the server will return that value as a 4-byte integer representing the number of days since 1899-12-31 (so 1900-01-01 was day 1), which is the internal representation of a DATE in Informix.
Something in a higher layer is then treating it as a 'date + time' value and assuming midnight is the time since there was no time component in the date, and is then rubbing salt in the wound by formatting it in am/pm notation.
This will involve client-side tracing of what's going on. My suspicion (not founded on anything except limited knowledge of the ODBC drivers) is that the problem is occurring in the .NET layers rather than the ODBC driver. However, you're way outside my area of expertise once you're above the ODBC layer (and I don't claim great expertise in ODBC).
You may be able to isolate the problem to the client code by using SQLIDEBUG=2:xyz in the environment (you might need to set that with SETNET32 for Windows). If it works at all on Windows (it does on Unix), then you'll end up with a file with a name starting xyz_ followed by various groups of digits and letters. That file can be analyzed by sqliprint and will show you what was sent to the Informix data server and returned to your client. Assuming the SQL was not hacked en route to the server, then you'll see the date returned as a simple date, and the problem is definitively client-side. If the SQL is hacked en route, then that too is a client-side problem.
It at least gives a starting point for debugging.
Look very carefully at the data types of the types your code is using. In particular, some DBMS have a DATE type that includes time information, and you may need to avoid that interpretation. The SQL standard has DATE (no time), TIME (no date) and TIMESTAMP (date and time) types.