Database Interface and MariaDB Driver.
RMariaDB
RMariaDB is a database interface and MariaDB driver for R. This version is aimed at full compliance with the DBI specification, as a replacement for the old RMySQL package.
Hello World
library(DBI)
# Connect to my-db as defined in ~/.my.cnf
con <- dbConnect(RMariaDB::MariaDB(), group = "my-db")
dbListTables(con)
dbWriteTable(con, "mtcars", mtcars)
dbListTables(con)
dbListFields(con, "mtcars")
dbReadTable(con, "mtcars")
# You can fetch all results:
res <- dbSendQuery(con, "SELECT * FROM mtcars WHERE cyl = 4")
dbFetch(res)
dbClearResult(res)
# Or a chunk at a time
res <- dbSendQuery(con, "SELECT * FROM mtcars WHERE cyl = 4")
while(!dbHasCompleted(res)){
chunk <- dbFetch(res, n = 5)
print(nrow(chunk))
}
# Clear the result
dbClearResult(res)
# Disconnect from the database
dbDisconnect(con)
Installation
Binary packages for OS X or Windows can be installed directly from CRAN:
install.packages("RMariaDB")
The development version from github:
# install.packages("devtools")
devtools::install_github("r-dbi/DBI")
devtools::install_github("r-dbi/RMariaDB")
Discussions associated with DBI and related database packages take place on R-SIG-DB. The website Databases using R describes the tools and best practices in this ecosystem.
Installation from source on Linux or OS X currently requires MariaDB Connector/C, preferably in version 2.3.4/3.0.3 or later. With older versions, character and blob columns do not work reliably. Alternatively, Oracle's libmysqlclient can be used.
Connector/C
On recent Debian or Ubuntu install libmariadb-dev.
sudo apt-get install -y libmariadb-dev
On Fedora, CentOS or RHEL we need mariadb-devel:
sudo yum install mariadb-devel
On OS X use mariadb-connector-c from Homebrew:
brew install mariadb-connector-c
MySQL client library
On recent Debian or Ubuntu install libmysqlclient-dev.
sudo apt-get install -y libmysqlclient-dev
On Fedora, CentOS or RHEL we need mysql-devel, see https://apps.fedoraproject.org/packages/mysql-devel:
sudo yum install mysql-devel
Follow instructions to enable the MySQL yum repository if the above command attempts to install MariaDB files.
On OS X use mysql-connector-c from Homebrew:
brew install mysql-connector-c++
MariaDB configuration file
Instead of specifying a username and password in calls to dbConnect(), it's better to set up a MariaDB configuration file that names the databases that you connect to most commonly. This file should live in ~/.my.cnf and look like:
[database_name]
option1=value1
option2=value2
If you want to run the examples, you'll need to set the proper options in the [rs-dbi] group of any MariaDB option file, such as /etc/my.cnf or the .my.cnf file in your home directory. For a default single user install of MariaDB, the following code should work:
[rs-dbi]
database="test"
user="root"
password=""
Acknowledgements
Many thanks to Christoph M. Friedrich, John Heuer, Kurt Hornik, Torsten Hothorn, Saikat Debroy, Matthew Kelly, Brian D. Ripley, Mikhail Kondrin, Jake Luciani, Jens Nieschulze, Deepayan Sarkar, Louis Springer, Duncan Temple Lang, Luis Torgo, Arend P. van der Veen, Felix Weninger, J. T. Lindgren, Crespin Miller, and Michal Okonlewski, Seth Falcon and Paul Gilbert for comments, suggestions, bug reports, and patches to the original RMySQL package, and to all contributors (of code and discussions) to this package.
Please note that the 'RMariaDB' project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.