R Code to connect to UNCC Vis DataLake (MongoDB) via mongolite

mongolite-datalake.R

# install mongolite if you do not have it
# see https://github.com/jeroen/mongolite
#install.packages("mongolite")
library(mongolite)

# replace with name of database -- change last folder to database (e.g., "gab")
mongoUrl <- "mongodb://datalake:27017/gab"

# change col to your collection
col <- "id"
# create connection (con)
con <- mongo(collection = col, url = mongoUrl)

# count how many records
con$count('{}')

# count how many records have a score greater than 3
out <- con$find('{"score" : { "$gt" : 3 } }')
nrow(out)

# get collection info info
info <- con$info()

# sample -- get five elements
con$find(limit = 5)

# get all posts (be careful if too large)
t <- con$find(fields = '{"body" : true}')

## how to query in mongolit
# see https://jeroen.github.io/mongolite/query-data.html#query-syntax

t2 <- con$find(
  query = '{"score" : { "$gt" : 3 } }', 
  fields = '{"id" : true, "created_at" : true, "body": true}',
  limit = 5
)

# indexing -- 
system.time(con$find(sort = '{"created_at" : 1}', limit = 100))

# query by date 
t3 <- con$find(
  query = '{"created_at": { "$gte" : { "$date" : "2016-10-19T01:35:26Z" }}}',
  fields = '{"id" : true, "created_at" : true, "body" : true, "_id": false}'
)

# aggregation & map-reduce https://jeroen.github.io/mongolite/calculation.html#aggregate

I just used this. Thanks for posting!