https://github.com/tidyverse/dbplyr

Database (DBI) backend for dplyr
https://github.com/tidyverse/dbplyr

database r

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Database (DBI) backend for dplyr

• Host: GitHub
• URL: https://github.com/tidyverse/dbplyr
• Owner: tidyverse
• License: other
• Created: 2017-03-28T20:29:16.000Z (over 7 years ago)
• Default Branch: main
• Last Pushed: 2024-06-25T11:10:26.000Z (3 months ago)
• Last Synced: 2024-06-27T12:54:56.025Z (3 months ago)
• Topics: database, r
• Language: R
• Homepage: https://dbplyr.tidyverse.org
• Size: 19 MB
• Stars: 468
• Watchers: 24
• Forks: 169
• Open Issues: 72
• Metadata Files:
  • Readme: README.Rmd
  • Contributing: .github/CONTRIBUTING.md
  • License: LICENSE
  • Code of conduct: .github/CODE_OF_CONDUCT.md
  • Codeowners: .github/CODEOWNERS
  • Support: .github/SUPPORT.md

Awesome Lists containing this project

• Road2R - dbplyr - A 'dplyr' Back End for Databases. (Table of Contents / Data manipulation)
• jimsghstars - tidyverse/dbplyr - Database (DBI) backend for dplyr (R)

README

        
---

output: github_document

---

```{r, echo = FALSE}

knitr::opts_chunk$set(

  collapse = TRUE,

  comment = "#>",

  fig.path = "README-"

)

```

# dbplyr 

[![CRAN status](https://www.r-pkg.org/badges/version/dbplyr)](https://cran.r-project.org/package=dbplyr)

[![R-CMD-check](https://github.com/tidyverse/dbplyr/actions/workflows/R-CMD-check.yaml/badge.svg)](https://github.com/tidyverse/dbplyr/actions/workflows/R-CMD-check.yaml)

[![Codecov test coverage](https://codecov.io/gh/tidyverse/dbplyr/branch/main/graph/badge.svg)](https://app.codecov.io/gh/tidyverse/dbplyr?branch=main)

## Overview

dbplyr is the database backend for [dplyr](https://dplyr.tidyverse.org). It allows you to use remote database tables as if they are in-memory data frames by automatically converting dplyr code into SQL. 

To learn more about why you might use dbplyr instead of writing SQL, see `vignette("sql")`. To learn more about the details of the SQL translation, see `vignette("translation-verb")` and `vignette("translation-function")`.

## Installation

```{r, eval = FALSE}

# The easiest way to get dbplyr is to install the whole tidyverse:

install.packages("tidyverse")

# Alternatively, install just dbplyr:

install.packages("dbplyr")

# Or the development version from GitHub:

# install.packages("pak")

pak::pak("tidyverse/dbplyr")

```

## Usage

dbplyr is designed to work with database tables as if they were local data frames. To demonstrate this I'll first create an in-memory SQLite database and copy over a dataset:

```{r setup}

library(dplyr, warn.conflicts = FALSE)

con <- DBI::dbConnect(RSQLite::SQLite(), ":memory:")

copy_to(con, mtcars)

```

Note that you don't actually need to load dbplyr with `library(dbplyr)`; dplyr automatically loads it for you when it sees you working with a database. Database connections are coordinated by the DBI package. Learn more at 

Now you can retrieve a table using `tbl()` (see `?tbl_dbi` for more details). Printing it just retrieves the first few rows:

```{r}

mtcars2 <- tbl(con, "mtcars")

mtcars2

```

All dplyr calls are evaluated lazily, generating SQL that is only sent to the database when you request the data.

```{r}

# lazily generates query

summary <- mtcars2 %>% 

  group_by(cyl) %>% 

  summarise(mpg = mean(mpg, na.rm = TRUE)) %>% 

  arrange(desc(mpg))

# see query

summary %>% show_query()

# execute query and retrieve results

summary %>% collect()

```

## Code of Conduct

Please note that the dbplyr project is released with a [Contributor Code of Conduct](https://dbplyr.tidyverse.org/CODE_OF_CONDUCT.html). By contributing to this project, you agree to abide by its terms.