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
teachersThe 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