Template
single collection
multiple collections
mgodatagen
update
indexe
explain
Stage
Database
bson
mgodatagen
[{_id:"1",name:"abc123",colors:[1,2,3]},{_id:"2",name:"abc123",colors:[4,2,1]}]
Query
db.collection.aggregate([{"$group":{"_id":null,"result":{"$addToSet":"$name"}}}])
Result