MongoDB Aggregation: Counting distinct fields

Question

I am trying to write an aggregation to identify accounts that use multiple payment sources. Typical data would be.

{
 account:\"abc\",
 vendor:\"amazon\",
}         


        

Answer 1

An example

db.collection.distinct("example.item").forEach( function(docs) {
    print(docs + "==>>" + db.collection.count({"example.item":docs}))
});