The magic I was looking for is to pass "as.is=TRUE" to "sqlQuery" of RODBC. The reference to "read.table" is a little oblique, but with that, all works fine.
An education! :-) Thanks much, Jan On Tue, 04 Aug 2009 09:05:05 +0200, "Peter Dalgaard" <p.dalga...@biostat.ku.dk> said: > Jan Theodore Galkowski wrote: > > Can someone point me to the proper place in the documentation or on the > > Wiki where I can learn how to get R to stop interpreting the string "NA" > > as something special? I have a table in a database which contains > > (among other things) country codes and continent codes. The standard > > set of two-letter codes includes "NA" to denote "North America". I > > learned of the "na.strings" parameter for RODBC's "sqlQuery", being able > > to shut down this interpretation when data is read in. > > > > However, in the program which uses this data, I (must) have some other > > instance where the "NA" gets spontaneously"interpreted as "not > > available", shows up in vectors and lists as "<NA>", and breaks > > function. I temporarily solved the problem by defining all instances of > > "NA" in the database as "NAC". It still would be good to know a > > generaly solution. I've seen something mentioned in conjunction with > > "options", but I'm not sure what that is about. > > The general paradigm is that this shouldn't happen... Back in the old > days, R had no such thing as character NA, and users had to sort out the > North America, noradrenaline, Neil Armstrong, etc., issues for > themselves. Nowadays we do have calculus that preserves "NA" as distinct > from <NA>; so if one is converted to the other, it could signify a bug. > > It could also be due to particularly silly code on your behalf, but in > either case we need to see the effect narrowed down to a reproducible > stretch of code. [snip] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
