How to remove multiple Documents from Mongo Database 

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 remove multiple documents from Mongo database.

File Name  :   com/bethecoder/tutorials/mongodb/tests/RemoveMultipleDocsTest.java  Author  :   Sudhakar KV Email  :   [email protected]

package com.bethecoder.tutorials.mongodb.tests; import java.net.UnknownHostException; import java.util.Arrays; import com.mongodb.BasicDBObject; import com.mongodb.DB; import com.mongodb.DBCollection; import com.mongodb.DBCursor; import com.mongodb.DBObject; import com.mongodb.Mongo; import com.mongodb.MongoException; public class RemoveMultipleDocsTest {   /**    * @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 for  num in [2, 4, 6]       DBObject query = new BasicDBObject();       query.put("num", new BasicDBObject("$in", Arrays.asList(2, 4, 6)));               //Removes the matching documents       collection.remove(query);              //Queries for all objects in this collection       DBCursor dbCursor = collection.find();       DBObject record = null;              while (dbCursor.hasNext()) {         record = dbCursor.next();         System.out.println(record);       }            } catch (UnknownHostException e) {       e.printStackTrace();     } catch (MongoException e) {       e.printStackTrace();     }   } }

{ "_id" : 1 , "num" : 1 , "even" : false , "num^2" : 1.0}
{ "_id" : 3 , "num" : 3 , "even" : false , "num^2" : 9.0}
{ "_id" : 5 , "num" : 5 , "even" : false , "num^2" : 25.0}
{ "_id" : 7 , "num" : 7 , "even" : false , "num^2" : 49.0}
{ "_id" : 8 , "num" : 8 , "even" : true , "num^2" : 64.0}
{ "_id" : 9 , "num" : 9 , "even" : false , "num^2" : 81.0}
{ "_id" : 10 , "num" : 10 , "even" : true , "num^2" : 100.0}
{ "_id" : 11 , "num" : 11 , "even" : false , "num^2" : 121.0}
{ "_id" : 12 , "num" : 12 , "even" : true , "num^2" : 144.0}
{ "_id" : 13 , "num" : 13 , "even" : false , "num^2" : 169.0}
{ "_id" : 14 , "num" : 14 , "even" : true , "num^2" : 196.0}
{ "_id" : 15 , "num" : 15 , "even" : false , "num^2" : 225.0}
{ "_id" : 16 , "num" : 16 , "even" : true , "num^2" : 256.0}
{ "_id" : 17 , "num" : 17 , "even" : false , "num^2" : 289.0}
{ "_id" : 18 , "num" : 18 , "even" : true , "num^2" : 324.0}
{ "_id" : 19 , "num" : 19 , "even" : false , "num^2" : 361.0}
{ "_id" : 20 , "num" : 20 , "even" : true , "num^2" : 400.0}