R help - May 2012 - Why does RODBC driver returns garbage from Sybase server on new windows 7 machine?

Hi, 

 I am trying to query a Sybase database on my new windows 7 machine.  I am
using native sybase driver "Adaptive server Enterprise" following is
example
code 

conn <- sprintf("driver=Adaptive server
Enterprise;server=PHKSESMD01;database=smd_live;uid=temp_user;password=temp_pass;port=2301")
chan <- odbcDriverConnect(conn) 
x <- sqlQuery(chan,sql,as.is=as.is) 
odbcClose(chan) 

I am able to connect to the database and get the data using above code. But
when the data is more than couple of hundred lines (4 columns.. its not
much), i get garbage data. I usually get 5 to 6 rows correctly and remaining
data is NAs.  Is this an issue with ODBC driver or issue with RODBC library?
I would think driver is ok because it works fine in other applications.  Can
someone suggest what could be wrong here and how to resolve it? 

Regards, 
Alok  



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On May 4, 2012, at 2:38 AM, Alok Jadhav wrote:
> Hi, 
> 
> I am trying to query a Sybase database on my new windows 7 machine.  I am
> using native sybase driver "Adaptive server Enterprise" following
is example
> code 
> 
> conn <- sprintf("driver=Adaptive server
>
Enterprise;server=PHKSESMD01;database=smd_live;uid=temp_user;password=temp_pass;port=2301")
> chan <- odbcDriverConnect(conn) 
> x <- sqlQuery(chan,sql,as.is=as.is) 
> odbcClose(chan) 
> 
> I am able to connect to the database and get the data using above code. But
> when the data is more than couple of hundred lines (4 columns.. its not
> much), i get garbage data. I usually get 5 to 6 rows correctly and
remaining
> data is NAs.  Is this an issue with ODBC driver or issue with RODBC
library?
> I would think driver is ok because it works fine in other applications. 
Can
> someone suggest what could be wrong here and how to resolve it? 
> 
> Regards, 
> Alok  


1. This query is better posted to r-sig-db, which is dedicated to R and DB
connectivity issues. More info at:

 https://stat.ethz.ch/mailman/listinfo/r-sig-db

2. It is not clear what 'as.is = as.is' in the call to sqlQuery is. Is
the value of 'as.is' defined before the call someplace else that you
have not shown here, along with the 'sql' query itself?

3. Try using 'rows_at_time = 1' as well as 'believeNRows =
FALSE' in the calls as below. That may help with corrupted data coming back.
I have to use the former with Oracle. That is also referenced in ?odbcConnect
with a comment specific to Sybase.

  chan <- odbcDriverConnect(conn, rows_at_time = 1, believeNRows = FALSE) 
  x <- sqlQuery(chan, sql, as.is = as.is, rows_at_time = 1, believeNRows =
FALSE)


Regards,

Marc Schwartz