How to count records with one distinct field in mongoose?

Question

While exploring mongoose for nodejs I ran into the problem of needing to know the amount of user in my collection:

My collection has records, each record has a user

Answer 1

Aggregation will work for you. Something like that:

Transaction.aggregate(
    { $match: { seller: user, status: 'completed'  } }, 
    { $group: { _id: '$customer', count: {$sum: 1} } }
).exec()