MongoDB deleteOne

Summary: in this tutorial, you’ll learn how to use the MongoDB deleteOne() method to delete a single document from a collection.

Introduction to the MongoDB deleteOn() method

The deleteOne() method allows you to delete a single document from a collection.

The deleteOne() method has the following syntax:

db.collection.deleteOne(filter, option)

The deleteOne() method accepts two arguments:

• filter is an required argument. The filter is a document that specifies the condition for matching the document to remove. If you pass an empty document {} into the method, it’ll delete the first document in the collection.
• option is an optional argument. The option is a document that specifies the deletion options.

The deleteOne() method returns a document containing the deleteCount field that stores the number of deleted documents.

To delete all documents that match a condition from a collection, you use the deleteMany() method.

MongoDB deleteCount() method examples

We’ll use the following products collection:

db.products.insertMany([
    { "_id" : 1, "name" : "xPhone", "price" : 799, "releaseDate": ISODate("2011-05-14"), "spec" : { "ram" : 4, "screen" : 6.5, "cpu" : 2.66 },"color":["white","black"],"storage":[64,128,256]},
    { "_id" : 2, "name" : "xTablet", "price" : 899, "releaseDate": ISODate("2011-09-01") , "spec" : { "ram" : 16, "screen" : 9.5, "cpu" : 3.66 },"color":["white","black","purple"],"storage":[128,256,512]},
    { "_id" : 3, "name" : "SmartTablet", "price" : 899, "releaseDate": ISODate("2015-01-14"), "spec" : { "ram" : 12, "screen" : 9.7, "cpu" : 3.66 },"color":["blue"],"storage":[16,64,128]},
    { "_id" : 4, "name" : "SmartPad", "price" : 699, "releaseDate": ISODate("2020-05-14"),"spec" : { "ram" : 8, "screen" : 9.7, "cpu" : 1.66 },"color":["white","orange","gold","gray"],"storage":[128,256,1024]},
    { "_id" : 5, "name" : "SmartPhone", "price" : 599,"releaseDate": ISODate("2022-09-14"), "spec" : { "ram" : 4, "screen" : 9.7, "cpu" : 1.66 },"color":["white","orange","gold","gray"],"storage":[128,256]}
 ])

1) Using the deleteOne() method to delete a single document

The following example uses the deleteOne() method to delete a document from the products collection where the _id is 1:

db.products.deleteOne({ _id: 1 })

The query returned the following document:

{ "acknowledged" : true, "deletedCount" : 1 }

The deleteCount field returned 1 indicating the number of deleted documents.

2) Using the deleteOne() method to delete the first document from a collection

The following query uses the deleteOne() method to remove the first document returned from the products collection:

db.products.deleteOne({})

It returned the following document:

{ "acknowledged" : true, "deletedCount" : 1 }

In this example, we passed an empty document {} to the deleteOne() method, therefore, it removed the first document from the products collection.

Summary

• Use the MongoDB deleteOne() method to remove a single document that matches a condition.
• Pass an empty document into the deleteOne() method to delete the first document from the collection.