MongoCollection.countDocuments

ulong countDocuments(T)(T filter, CountOptions options = CountOptions.init)

Returns the count of documents that match the query for a collection or view.

The method wraps the $group aggregation stage with a $sum expression to perform the count.

Throws Exception if a DB communication error occurred.

See Also

https://www.mongodb.com/docs/manual/reference/method/db.collection.countDocuments/