Hi,
Has anyone seen this problem before, and does anyone have a solution?
When I query a database using DBI and ROracle to retrieve a date in a format
other than the system default, I get a core dump.
System: Redhat Linux 7.3
uname: Linux 2.4.20-20.7smp #1 SMP Mon Aug 18 14:46:14 EDT 2003 i686
Oracle version 8i
R --version: R 1.7.1 (2003-06-16).
DBI_0.1-6, ROracle_0.5-0
Start up R, load libraries and create a connection to
DB:> library(DBI)
> library(ROracle)
> conn <- dbConnect("Oracle", dbname='EPIMS',
user='XXX', pass='XXX')
Here is an example of a query that works:> d <- dbGetQuery(conn,
'SELECT HybridDate FROM Hybridization WHERE
ExperimentID=2717')> str(d)
`data.frame': 54 obs. of 1 variable:
$ HYBRIDDATE: chr "22-MAY-2003 00:00:00" "22-MAY-2003
00:00:00" "17-JUL-2003
00:00:00" "17-JUL-2003 00:00:00" ...
Here is a query which dumps core (the sql is all on one
line):> d <- dbGetQuery(conn,
"SELECT TO_CHAR(HybridDate, 'YYYY-MM-DD') FROM Hybridization WHERE
ExperimentID=2717")
Segmentation fault (core dumped)
My current work around is to accept the Oracle default date format and then
use R's strpdate to convert to a date format that I want. I don't like
coding
this way, however, as it relies on the Oracle date format remaining static; I
prefer to code more 'defensively'.
I assume this is a bug in DBI/ROracle processing of functions in the selected
variables, but I don't know. Any suggestions are welcome.
Thanks,
Mark
--
Mark Dalphin email: mdalphin at amgen.com
Mail Stop: 29-2-A phone: +1-805-447-4951 (work)
One Amgen Center Drive +1-805-375-0680 (home)
Thousand Oaks, CA 91320 fax: +1-805-499-9955 (work)
