MongoDB distinct aggregation

Question

I\'m working on a query to find cities with most zips for each state:

db.zips.distinct(\"state\", db.zips.aggregate([ {$group:{_id:{state:\"$state\", city:\"         


        

Answer 1

You can use $addToSet with the aggregation framework to count distinct objects.

For example:

db.collectionName.aggregate([{
    $group: {_id: null, uniqueValues: {$addToSet: "$fieldName"}}
}])