MongoDB deleteMany

Summary: in this tutorial, you’ll learn how to use the MongoDB deleteMany() method to delete all documents that match a condition from a collection.

Introduction to MongoDB deleteMany() method

The deleteMany() method allows you to remove all documents that match a condition from a collection.

The deleteMany() has the following syntax:

db.collection.deleteMany(filter, option)

In this syntax:

• filter is a document that specifies deletion criteria. If the filter is an empty document {}, the deleteMany() method will delete all documents from the collection.
• option is a document that specifies the deletion option.

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

To delete a single document from a collection, you can use the deleteOne() method.

MongoDB deleteMany() 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 deleteMany() method to delete multiple documents

The following example uses the deleteMany() method to delete all documents where the value in the price field is 899:

db.products.deleteMany({ price: 899 })

In this example, the filter argument is { price: 899 } that matches documents whose price is 899.

It returned the following document:

{ "acknowledged" : true, "deletedCount" : 2 }

The deleteCount field indicates that the number of deleted documents is 2.

2) Using the deleteMany() method to delete all documents

The following query uses the deleteMany() method to delete all documents from the products collection:

db.products.deleteMany({})

In this example, we passed an empty document {} into the deleteMany() method, therefore, it deleted all documents from the products collection.

Summary

• Use the deleteMany() method to remove all documents that match a condition from a collection.
• Pass an empty document {} into the deleteMany() method to remove all documents from the collection.