How to drop a MongoDB Collection using Java?

JavaObject Oriented ProgrammingProgramming

You can drop an existing collection from MongoDB using the drop() method.

Syntax

db.coll.drop()

Where,

  • db is the database.

  • coll is the collection (name) in which you want to insert the document

Example

Assume we have created 3 collections in a MongoDB database as shown below −

> use sampleDatabase
switched to db sampleDatabase
> db.createCollection("students")
{ "ok" : 1 }
> db.createCollection("teachers")
{ "ok" : 1 }
> db.createCollection("sample")
{ "ok" : 1 }
> show collections
sample
students
teachers

The following query deletes the collection named sample.

> db.sample.drop()
true
> show collections
example
students
teachers

Using Java program

In Java, you can drop a collection using the in the current collection using the drop() method of the com.mongodb.client.MongoCollection interface.

Therefore to drop a collection in MongoDB using Java program −

  • Make sure you have installed MongoDB in your system

  • Add the following dependency to its pom.xml file of your Java project.

<dependency>
   <groupId>org.mongodb</groupId>
   <artifactId>mongo-java-driver</artifactId>
   <version>3.12.2</version>
</dependency>
  • Create a MongoDB client by instantiating the MongoClient class.

  • Connect to a database using the getDatabase() method.

  • Get the object of the collection you want to drop, using the getCollection() method.

  • Drop the collection by invoking the drop() method.

Example

import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoIterable;
import com.mongodb.MongoClient;
public class DropingCollection {
   public static void main( String args[] ) {
      //Creating a Mongo client
      MongoClient mongo = new MongoClient( "localhost" , 27017 );
      //Connecting to the database
      MongoDatabase database = mongo.getDatabase("mydatabase");
      //Creating multiple collections
      database.createCollection("sampleCollection1");
      database.createCollection("sampleCollection2");
      database.createCollection("sampleCollection3");
      database.createCollection("sampleCollection4");
      //Retrieving the list of collections
      MongoIterable<String> list = database.listCollectionNames();
      System.out.println("List of collections:");
      for (String name : list) {
         System.out.println(name);
      }
      database.getCollection("sampleCollection4").drop();
      System.out.println("Collection dropped successfully");
      System.out.println("List of collections after the delete operation:");
      for (String name : list) {
         System.out.println(name);
      }
   }
}

Output

List of collections:
sampleCollection4
sampleCollection1
sampleCollection3
sampleCollection2
Collection dropped successfully
List of collections after the delete operation:
sampleCollection1
sampleCollection3
sampleCollection2
raja
Published on 10-Apr-2020 08:37:00
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