The goal of mongopipe is to have a simple translator for R code into json based queries for Mongodb.
You can install the released version of mongopipe from CRAN with:
install.packages("mongopipe")or install the development version of mongopipe on gitlab with:
remotes::install_gitlab("illoRocks/mongopipe")library(mongopipe)
library(mongolite)
library(nycflights13)
m_flights <- mongo("test_flights", verbose = FALSE)
m_airports <- mongo("test_airports", verbose = FALSE)
if(!m_flights$count())
m_flights$insert(flights)
if(!m_airports$count())
m_airports$insert(airports)
result <- mongopipe() %>%
match(faa="ABQ") %>%
lookup(from = "test_flights", local_field = "faa", foreign_field = "dest") %>%
unwind(field = "test_flights") %>%
project(air_time="$test_flights.air_time", dep_delay="$test_flights.dep_delay", origin="$test_flights.origin") %>%
m_airports$aggregate()
head(result)
#> _id air_time dep_delay origin
#> 1 5fe23ddb5a72ab3dc0076731 230 -6 JFK
#> 2 5fe23ddb5a72ab3dc0076731 238 9 JFK
#> 3 5fe23ddb5a72ab3dc0076731 251 -6 JFK
#> 4 5fe23ddb5a72ab3dc0076731 257 16 JFK
#> 5 5fe23ddb5a72ab3dc0076731 242 0 JFK
#> 6 5fe23ddb5a72ab3dc0076731 240 -2 JFKpipe <- mongopipe() %>%
match(faa="ABQ") %>%
lookup(from = "test_flights", local_field = "faa", foreign_field = "dest") %>%
unwind(field = "test_flights") %>%
project(air_time="$test_flights.air_time", dep_delay="$test_flights.dep_delay", origin="$test_flights.origin")
print(pipe, pretty = 4)
#> [
#> {
#> "$match": {
#> "faa": "ABQ"
#> }
#> },
#> {
#> "$lookup": {
#> "from": "test_flights",
#> "localField": "faa",
#> "foreignField": "dest",
#> "as": "test_flights"
#> }
#> },
#> {
#> "$unwind": "$test_flights"
#> },
#> {
#> "$project": {
#> "air_time": "$test_flights.air_time",
#> "dep_delay": "$test_flights.dep_delay",
#> "origin": "$test_flights.origin"
#> }
#> }
#> ]