BE THE CODER > No SQL > Mongo DB Examples

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 use like Query in Mongo database.

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


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.DBCursor;

import com.mongodb.Mongo;

import com.mongodb.MongoException;



public class LikeQueryTest {

  

  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 db = mongo.getDB("mytestdb");



      // Get the collection from MongoDB

      DBCollection collection = db.getCollection("students");



      // Search query

      System.out.println("--- All Documents ---");

      BasicDBObject searchQuery = new BasicDBObject();

      printResults(collection, searchQuery);

      

      System.out.println("--- Results for name like '^Sri'---");

      searchQuery = new BasicDBObject();

      searchQuery.put("name", java.util.regex.Pattern.compile("^Sri")); //starts with 'Sri'

      printResults(collection, searchQuery);

      

      System.out.println("--- Results for name like 'kar$'---");

      searchQuery = new BasicDBObject();

      searchQuery.put("name", java.util.regex.Pattern.compile("kar$")); //ends with 'kar'

      printResults(collection, searchQuery);

      

      System.out.println("--- Results for name like '.*a.*'---");

      searchQuery = new BasicDBObject();

      searchQuery.put("name", java.util.regex.Pattern.compile(".*a.*")); //contains 'a'

      printResults(collection, searchQuery);



    } catch (UnknownHostException e) {

      e.printStackTrace();

    } catch (MongoException e) {

      e.printStackTrace();

    }

  }

  

  private static void printResults(DBCollection collection, BasicDBObject searchQuery) {

    

    DBCursor cursor = collection.find(searchQuery);

    

    // loop over the cursor and display the retrieved result

    while (cursor.hasNext()) {

      System.out.println(cursor.next());

    }

    System.out.println();

  }

}

How to use Like Query