[R] RODBC sqlFetch

[juli g. pausas]

Richard and F. Tussell,
Thank you very much for your explanations and suggestions.

Richard, and any
See my reply below.



Richard Rowe ha escrito:

> At 18:03 11/05/02 +0100, you wrote:
> >Hi,
> >Thanks for showing me how to use RODBC and odbcConnect.
> >Now works nicely. The question I've got now is:
> >
> >noms <- list.files(pattern=".DBF")
> ># removing extension names:
> >noms <- sapply(noms, function(x) as.character(strsplit(x,".DBF")) ,
> >USE.NAMES=F)
> >
> >for (i in 1:length(noms))  {
> >        s <- sqlFetch(bdades, noms[i])
> ># etc.
> >}
> >
> >But it seems that sqlFetch() doesn't accept the name noms[i]. Neither
> >paste(noms[1], sep = "").
> >Any suggestion for workaround?
>
> Don't know but two suggestions
>
> 1) are the tables {noms} actually tables in the database which is linked
> with the handle bdades?  If they are separate databases then they will
> require separate DSN handles to link ...

I think this is not needed. dbaseclima is the DSN for  a subdiretory (Panel
control, ...), and after
bdades <- odbcConnect("dbaseclima")
I'm able to access to all tables in the subdirectory, without any problem.
The problem is when I want to use the name of a table as an item of an array
of names (noms[i], see below)



> Solution: do some adjusting in the database so the various noms tables are
> in the same database
>
> 2) the characters '[' and ']' seem to have special properties to pass
> names, so noms[i] may not be being interpreted as the i-th member of
> 'noms'  ... as I said earlier I don't know the detail of this construction
>
> Solution: name the table first
>
> >for (i in 1:length(noms))  {
>
>            nomfornow<-noms[i]  ## and you will need to ensure there are
> quote marks around nomfornow
>
> >        s <- sqlFetch(bdades, nomfornow)

I did try this option, but unfortunatly didn't work:

>noms <- list.files(pattern=".DBF")
># removing extension names:
>noms <- sapply(noms, function(x) as.character(strsplit(x,".DBF")) ,
USE.NAMES=F)
>
> nom <- noms[1]
> s <- sqlFetch(bdades, nom)
Error in sqlFetch(bdades, nom) : nom :table not found on channel 0
> nom
[1] "R7031"
> s <- sqlFetch(bdades, "R7031")  # this works perfectly
>


I got ca. 200 files I'd like to read, this is why I would like to use noms[i].

cheers

Juli




> ># etc.
> >}
>
> Richard Rowe
> Senior Lecturer
> Department of Zoology and Tropical Ecology, James Cook University
> Townsville, Queensland 4811, Australia
> fax (61)7 47 25 1570
> phone (61)7 47 81 4851
> e-mail: Richard.Rowe at jcu.edu.au
> http://www.jcu.edu.au/school/tbiol/zoology/homepage.html

--
Juli G. Pausas
Centro de Estudios Ambientales del Mediterraneo (CEAM)
C/ C.R. Darwin 14, Parc Tecnologic,
46980 Paterna, Valencia, SPAIN
Tel: (+ 34) 96 131 8227; Fax: (+ 34) 96 131 8190
mailto:juli at ceam.es
http://www.gva.es/ceam

GCTE Fire Network - http://www.gva.es/ceam/FireNetwork


-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._