[R] SQL Primer for R
Gabor Grothendieck
ggrothendieck at gmail.com
Mon Aug 25 15:24:49 CEST 2008
The sqldf package's home page
http://sqldf.googlecode.com
has quite a few examples as well as links to resources. Also see the
examples in ?sqldf
On Mon, Aug 25, 2008 at 9:12 AM, ivo welch <ivowel at gmail.com> wrote:
> Dear R wizards:
>
> I decided to take the advice in the R data import/export manual and
> want to learn how to work with SQL for large data sets. I am trying
> SQLite with the DBI and RSQLite database interfaces. Speed is nice.
> Alas, I am struggling to find a tutorial that is geared for the kind
> of standard operations that I would want in R. Simple things:
>
> * how to determine the number of rows in a table. (Of course, I
> could select a row of data and then use this.)
>
> * how to insert a new column into my existing SQL table---say, the
> rank of another variable---and save it back. Am I supposed to create
> a new data frame, then save it as a new table, then delete the old SQL
> table?
>
> * how to save a revised version of my table in a different sort order
> (with or without deleting the original table). <-- I guess this is
> not appropriate, as I should think of SQL tables as unordered.
>
> I guess these would make nice little text snippets in the R Data
> import/export manual, too. help appreciated.
>
> regards,
>
> /ivo
>
> ______________________________________________
> R-help at 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.
>
More information about the R-help
mailing list