Cara menggunakan mongodb countdocuments performance

Example

The following example estimates the number of documents in the MongoCollection1 collection in the MongoCollection2 database, and then returns an accurate count of the number of documents in the MongoCollection1 collection with MongoCollection4 in the MongoCollection5 field.

Note

This example connects to an instance of MongoDB using a connection URI. To learn more about connecting to your MongoDB instance, see the

package usage.examples;
import static com.mongodb.client.model.Filters.eq;
import org.bson.Document;
import org.bson.conversions.Bson;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
public class CountDocuments {
    public static void main(String[] args) {
        // Replace the uri string with your MongoDB deployment's connection string
        String uri = "<connection string uri>";
        try (MongoClient mongoClient = MongoClients.create(uri)) {
            MongoDatabase database = mongoClient.getDatabase("sample_mflix");
            MongoCollection<Document> collection = database.getCollection("movies");
            Bson query = eq("countries", "Spain");
            try {
                long estimatedCount = collection.estimatedDocumentCount();
                System.out.println("Estimated number of documents in the movies collection: " + estimatedCount);
                long matchingCount = collection.countDocuments(query);
                System.out.println("Number of movies from Spain: " + matchingCount);
            } catch (MongoException me) {
                System.err.println("An error occurred: " + me);
            }
        }
    }
}

If you run the preceding sample code, you should see output that looks something like this (exact numbers may vary depending on your data):

Estimated number of documents in the movies collection: 23541
Number of movies from Spain: 755

Tip

Legacy API

If you are using the legacy API, to learn what changes you need to make to this code example.

For additional information on the classes and methods mentioned on this page, see the following API Documentation: