I tried to run this query and keep having this error:
install.packages(“mongolite”)
library(mongolite)
m <- mongo(db = "ionmom")
m6 <- m$aggregate('[{"$unwind":"$cdr"}, {$lookup:{from: "inventory", localField: "_id", foreignField: "_id", as:"inventory"}},{$unwind: "$inventory"}, {"$project":{ "$project": {"cdr.duration": 1, "inventory.wearables.type":1, "inventory.wearables.status":1, "inventory.wearables.battery":1 }}}]')
# Error: Invalid JSON object: [{"$unwind":"$cdr"}, {$lookup:{from: "inventory", localField: "_id", foreignField: "_id", as:"inventory"}},{$unwind: "$inventory"}, {"$project":{ "$project": {"cdr.duration": 1, "inventory.wearables.type":1, "inventory.wearables.status":1, "inventory.wearables.battery":1 }}}]
2 Answers
mongolite uses jsonlite under the hood to do the JSON parsing. If you put your query through jsonlite::fromJSON() you'll see the issue
js <- '[{"$unwind":"$cdr"}, {$lookup:{from: "inventory", localField: "_id", foreignField: "_id", as:"inventory"}},{$unwind: "$inventory"}, {"$project":{ "$project": {"cdr.duration": 1, "inventory.wearables.type":1, "inventory.wearables.status":1, "inventory.wearables.battery":1 }}}]'
jsonlite::fromJSON(js)
# Error: lexical error: invalid char in json text.
# [{"$unwind":"$cdr"}, {$lookup:{from: "inventory", loc
# (right here) ------^
This is telling you the JSON structure is invalid, because it's expecting quotes " " around each string
js <- '[{"$unwind":"$cdr"}, {"$lookup":{"from": "inventory", "localField": "_id", "foreignField": "_id", "as":"inventory"}},{"$unwind": "$inventory"}, {"$project":{ "$project": {"cdr.duration": 1, "inventory.wearables.type":1, "inventory.wearables.status":1, "inventory.wearables.battery":1 }}}]'
m$aggregate(js)
## I don't have your data ...
# Imported 0 records. Simplifying into dataframe...
# data frame with 0 columns and 0 rows
Try to add:
js <- '[{"$unwind":"$cdr"}, {"$lookup":{"from": "inventory", localField:}]'
