dbframe-package: An overview of the dbframe package
In grayclhn/dbframe-R-library: An R to SQL interface

Description Details Author(s) References Examples

This package and documentation are very much under development. Right now, it only provides an interface with sqlite databases and has untested code that will try to guess the right interface for other databases. The function dbframe creates a new dbframe object associated with one of the tables in an sqlite database. Queries on the database can then be executed through the dbframe object's methods. This package also provides some convenient functions for printing and manipulating data frames, but its main role is to make it easier to write queries.

This package is a collection of functions that I'm developing to work more easily with databases. I find it annoying to have to type sql statements into functions like dbSendQuery, etc. to explicitly pull data from a database into an R dataframe, especially since I often forget the details of sql. When the database is updated regularly, this is especially annoying since the R dataframe gets out of date and the sql statement needs to be executed again. This package is my attempt automate this sort of routine use of sql. I've tried to make the syntax look more “R-like” than, eg, DBI. Please let me know if you have any suggestions for functionality, appearance, or syntax.

Queries

So far, I've just implemented insert and select queries. insert allows you to insert new records into a database from an R data frame. select allows you to retrieve those records from the data base. select also allows some basic data analysis, more or less anything that is available as an aggregate function in the sql database.

Notes on implementation

I'm attempting to make this package a literate program (Knuth, 1984). That means that the source code is embedded in the documentation. The “implementation” section of each help page presents and discusses the source code for its functions. Right now, the formatting is pretty rudimentary, but I hope to improve the appearance at some point.

This package is currently in alpha. I use it in my research and will add functionality as I need it, but I don't have the time to extend it in some obviously important directions that are unrelated to my workflow. I plan to do so in the future, though, and even now would like to implement specific requests if people are interested.

Gray Calhoun gcalhoun@iastate.edu

Knuth, Donald E., Literate Programming. The Computer Journal, 27(2):97–111, 1984.

filename <- tempfile(fileext = ".db")
example.dbframe <- dbframe("package1", dbname = filename, clear = TRUE)
data(chickwts)
insert(example.dbframe) <- chickwts
select(example.dbframe, "avg(weight)", group.by = "feed")
unlink(filename)