Node.js - MongoDB Delete

The mongodb driver for Node.js includes two methods in the Collection class. The deleteOne() method deletes one document, whereas the deleteMany() method is used to delete more than on documents at a time. Both the methods need a filter argument.

collection.deleteOne(filter);

Note that if there are more than one documents that satisfy the given filter condition, only the first document is deleted.

deleteOne()

In the following example. The deleteOne() method removes a document from products collection, whose name field matches TV.

const {MongoClient} = require('mongodb');
async function main(){

   const uri = "mongodb://localhost:27017/";
   const client = new MongoClient(uri);

   try {
      await client.connect();
      await deldocs(client, "mydb", "products");
   } finally {
      await client.close();
   }
}

main().catch(console.error);


async function deldocs(client, dbname, colname){
   var myqry = { Name: "TV" };
   const result = await client.db(dbname).collection(colname).deleteOne(myqry);
   console.log("Document Deleted");
}

Use MongoCompass (or MongoShell) to verify if the expected document has been removed after the above code is executed.

deleteMany()

The deleteMany() method also use the filter argument. However, it causes all the document satisfying the specified condition will be removed.

In the code above, change the deldocs() function as follows. It results in all the documents with price>10000 to be removed.

async function deldocs(client, dbname, colname){
   var myqry = {"price":{$gt:10000}};
   const result = await client.db(dbname).collection(colname).deleteMany(myqry);
   console.log("Documents Deleted");
}

Drop Collection

You can remove a collection from the database with drop() method.

Example

const {MongoClient} = require('mongodb');

async function main(){

   const uri = "mongodb://localhost:27017/";
   const client = new MongoClient(uri);

   try {
      await client.connect();
      await dropcol(client, "mydb", "products");
   } finally {
      await client.close();
   }
}
main().catch(console.error);


async function dropcol(client, dbname, colname){
   const result = await client.db(dbname).collection(colname).drop();
   console.log("Collection dropped ");

}

There is also a dropCollection() method available with the db object.

const {MongoClient} = require('mongodb');
async function main(){
   
	const uri = "mongodb://localhost:27017/";
   const client = new MongoClient(uri);

   try {
      await client.connect();
      await dropcol(client, "mydb", "orders");
   } finally {
      await client.close();
   }
}

main().catch(console.error);

async function dropcol(client, dbname, colname){
   const result = await client.db(dbname).dropCollection(colname);
   console.log("Collection dropped");
}