README.md

In hoesler/dbj: Provides access to databases through the JDBC interface

dbj

dbj is an R package implementing DBI 0.4 using JDBC via rJava.

Requirements

• Java 6+

Installation

dbj can be installed most easily using the devtools package. After you have installed devtools, just run devtools::install_github("hoesler/dbj").

The source compilation requires that you have maven installed.

Usage

library(DBI)
library(dbj)

# Initially, register the JDBC drivers you need
jdbc_register_driver(
 'org.h2.Driver',
 resolve(
   module('com.h2database:h2:1.3.176'),
   repositories = list(maven_local, maven_central) )
)

con <- dbConnect(dbj::driver(), 'jdbc:h2:mem:')
dbWriteTable(con, "iris", iris)

# dbj supports prepared statements
sql <- paste0(
  "SELECT * FROM ", dbQuoteIdentifier(con, "iris"),
  " WHERE ", dbQuoteIdentifier(con, "Species"), " = ?"
)
dbGetQuery(con, sql, parameters = list("setosa"))

Status

No version has been releaded yet. dbj is under active development and tested agains different JDBC drivers using DBItest:

• H2
• Apache Derby
• MySQL Connector/J
• more to come...

Type mapping

The default type mapping between R and SQL is (roughly) as follows:

R classes | SQL types ------------------|----------------- logical | BIT, BOOLEAN numeric | FLOAT, REAL, DOUBLE, NUMERIC, DECIMAL, BIGINT integer | TINYINT, SMALLINT, INTEGER, NULL character, factor | CHAR, VARCHAR, LONGVARCHAR, NCHAR, NVARCHAR, LONGNVARCHAR Date | DATE difftime | TIME POSIXct | TIMESTAMP list(raw) | BINARY, BLOB

Acknowledgements

dbj is a rewrite of Simon Urbanek's RJDBC packge. Development started with only minor code modifications to meet the requirements of the devtools package development tools and the design guidelines for good R packages (See R packages by Hadley Wickham). In the end, the code diverged too far to merge it back into RJDBC.

hoesler/dbj documentation built on May 17, 2019, 4:36 p.m.