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<!-- README.md is generated from README.Rmd. Please edit that file -->
RSQLite
=======
[](https://travis-ci.org/rstats-db/RSQLite) [](https://ci.appveyor.com/project/rstats-db/RSQLite) [](https://codecov.io/github/rstats-db/RSQLite?branch=master)
Embeds the SQLite database engine in R, providing a DBI-compliant interface. [SQLite](http://www.sqlite.org) is a public-domain, single-user, very light-weight database engine that implements a decent subset of the SQL 92 standard, including the core table creation, updating, insertion, and selection operations, plus transaction management.
You can install the latest released version from CRAN with:
``` r
install.packages("RSQLite")
```
Or install the latest development version from GitHub with:
``` r
# install.packages("devtools")
devtools::install_github("rstats-db/RSQLite")
```
To install from GitHub, you'll need a [development environment](http://www.rstudio.com/ide/docs/packages/prerequisites).
Basic usage
-----------
``` r
library(DBI)
# Create an ephemeral in-memory RSQLite database
con <- dbConnect(RSQLite::SQLite(), ":memory:")
dbListTables(con)
```
## character(0)
``` r
dbWriteTable(con, "mtcars", mtcars)
```
## [1] TRUE
``` r
dbListTables(con)
```
## [1] "mtcars"
``` r
dbListFields(con, "mtcars")
```
## [1] "row_names" "mpg" "cyl" "disp" "hp"
## [6] "drat" "wt" "qsec" "vs" "am"
## [11] "gear" "carb"
``` r
dbReadTable(con, "mtcars")
```
## mpg cyl disp hp drat wt qsec vs am gear carb
## Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4
## Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4
## Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1
## Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1
## Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2
## Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3 1
## Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4
## Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2
## Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2
## [ reached getOption("max.print") -- omitted 23 rows ]
``` r
# You can fetch all results:
res <- dbSendQuery(con, "SELECT * FROM mtcars WHERE cyl = 4")
dbFetch(res)
```
## mpg cyl disp hp drat wt qsec vs am gear carb
## Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1
## Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2
## Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2
## Fiat 128 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1
## Honda Civic 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2
## Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1
## Toyota Corona 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3 1
## Fiat X1-9 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4 1
## Porsche 914-2 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5 2
## [ reached getOption("max.print") -- omitted 2 rows ]
``` r
dbClearResult(res)
```
## [1] TRUE
``` r
# 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))
}
```
## [1] 5
## [1] 5
## [1] 1
``` r
# Clear the result
dbClearResult(res)
```
## [1] TRUE
``` r
# Disconnect from the database
dbDisconnect(con)
```
## [1] TRUE
Acknowledgements
----------------
Many thanks to Doug Bates, Seth Falcon, Detlef Groth, Ronggui Huang, Kurt Hornik, Uwe Ligges, Charles Loboz, Duncan Murdoch, and Brian D. Ripley for comments, suggestions, bug reports, and/or patches.
|
