ruby on rails - An Hash with aggregation framework -

i using rails mongoid, syntax language.

my mongodb objects these:

{ "_id" : "asset01_*00001", "total" : 124 ...}, { "_id" : "asset01_*00002", "total" : 99 ...}, {...}

the project operator is:

{"project" => {"_id" => 1, "pair" => {"$add" => {"$_id" => "$total"}} }}

and group operator is:

{"$group" => { "invoice" => { "$push" => "$pair"} }}

but throws following error:

the $add operator not accept object operand

i know meaning of error, have alternative problem?

the result is:

{ "_id" => 1, "pair" => {"asset01_*00001" => 124, "asset01_*00002" => 99 ... }

a hash of {asset_id => number}

thanks

you want transform field values keys in results.

unfortunately that's not possible, there a feature request it can vote in mongodb jira system.

GHI