Is it possible to combine two Json with Ruby in MongoDB? - json

Question

I have to insert documents in my Mongo database by using Ruby (not on Rails, on Notepad++), many documents have duplicates with some modifications.
I want to write a script which use a json file, read it, import it in MongoDB by checking if each documents do not have any duplicate in the database, and if there is a duplicate I want to combine it if it contains any additional information:
Such as :
Document 1
{ "Name" : "Lila",
"Files":
[
{ "Name": "File1", "Date" : "05-11-2017"},
{ "Name": "File2", "Date" : "26-03-2018"}
]
}
Document 2
{ "Name" : "Lila",
"Files":
[
{ "Name": "File3", "Date" : "26-03-2018"}
]
}
Combine them to have:
{ "Name" : "Lila",
"Files":
[
{ "Name": "File1", "Date" : "05-11-2017"},
{ "Name": "File2", "Date" : "26-03-2018"},
{ "Name": "File3", "Date" : "26-03-2018"}
]
}
I founded that it is possible in mongo shell thanks to the aggregation-accumulation $mergeObjects, but in Ruby it do not seems to exists.

Answer 1

You can use all the operators in ruby, too. You need to get the underlying collection object first.
require 'mongo'
db = Mongo::Connection.new.db("mydb")
coll = db.collection('posts')
coll.aggregate([
{"$project" => {"last_name" => 1, "first_name" => 1 }},
{"$match" => {"last_name" => "Jones"}}
])
This is an example pipeline. You can give the same aggregation pipeline that worked for you on the mongo shell to aggregate.
For more information, refer to the MongoDB Ruby driver documentation:
http://www.rubydoc.info/gems/mongo/1.8.2/Mongo%2FCollection%3Aaggregate