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 No SQL > Mongo DB > How to get first document from Collection

How to get first document from Collection 

MongoDB is a scalable, high-performance, open source NoSQL database. It offers Ad hoc queries, Indexing, Replication, Load balancing, File storage (GridFS), Aggregation, MapReduce and Server-side JavaScript execution. This requires the library mongo-2.8.0.jar to be present in the classpath. The following example shows how to get the first document from collection matching the query.

File Name  :  
com/bethecoder/tutorials/mongodb/tests/FindOneTest.java 
Author  :  Sudhakar KV
Email  :  kvenkatasudhakar@gmail.com
   
package com.bethecoder.tutorials.mongodb.tests;

import java.net.UnknownHostException;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBObject;
import com.mongodb.Mongo;
import com.mongodb.MongoException;

public class FindOneTest {

  /**
   @param args
   */
  public static void main(String[] args) {

    try {
      //Connect to mongoDB with given IP and PORT
      Mongo mongo = new Mongo("localhost"27017);
      
      //Get the database object
      DB database = mongo.getDB("mytestdb");
      
      //Gets a collection with a given name.
      DBCollection collection = database.getCollection("mynums");
      
      //Query and get the first object from this collection matching the query
      DBObject query = new BasicDBObject().append("even"true);
      DBObject firstEven = collection.findOne(query);
      System.out.println(firstEven);
      
    catch (UnknownHostException e) {
      e.printStackTrace();
    catch (MongoException e) {
      e.printStackTrace();
    }
  }
}
   

It gives the following output,
{ "_id" : 2 , "num" : 2 , "even" : true , "num^2" : 4.0}


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