extras/dplyr_modulo.md

In WinVector/rquery: Relational Query Generator for Data Manipulation at Scale

dplyr modulo

library("dplyr")

## 
## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
## 
##     filter, lag

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

postgresql_connection <- DBI::dbConnect(
  RPostgreSQL::PostgreSQL(),
  host = 'localhost',
  port = 5432,
  user = 'johnmount',
  password = '')

d <- data.frame(x = -3:3)
d_db <- dplyr::copy_to(postgresql_connection, d, "d")

d %>%
  mutate(x_mod_2 = x %%2)

##    x x_mod_2
## 1 -3       1
## 2 -2       0
## 3 -1       1
## 4  0       0
## 5  1       1
## 6  2       0
## 7  3       1

d_db %>%
  mutate(x_mod_2 = x %%2)

## # Source:   lazy query [?? x 2]
## # Database: postgres 10.4.0 [johnmount@localhost:5432/johnmount]
##       x x_mod_2
##   <int>   <dbl>
## 1    -3      -1
## 2    -2       0
## 3    -1      -1
## 4     0       0
## 5     1       1
## 6     2       0
## 7     3       1

DBI::dbDisconnect(postgresql_connection)

## [1] TRUE

WinVector/rquery documentation built on Aug. 24, 2023, 11:12 a.m.