In MongoDB, you are allowed to delete the existing documents from the collection using db.collection.deleteMany() method. This method deletes multiple documents from the collection according to the filter.

deleteMany() is a mongo shell method, which can delete multiple documents. This method can be used in the multi-document transactions. If you use this method in capped collection, then it will throw an exception.

Syntax:

db.collection.deleteMany(
    <filter>,
   {
      writeConcern: <document>,
     collation: <document>
   }
)

Parameters:

fileter: First parameter of this method. It specifies the selection criteria for the delete using query operators. The type of this parameter is document. If it contains empty document, i.e, {}, then this method will delete all the documents from the collection.

Optional Parameters:

• writeConcern: It is only used when you do not want to use the default write concern. The type of this parameter is document.
• collation: It specifies the use of the collation for operations. It allows users to specify the language-specific rules for string comparison like rules for lettercase and accent marks. The type of this parameter is document.

Return: This method will return a document that contains a boolean acknowledged as true (if the write concern is enabled) or false (if the write concern is disabled) and deletedCount that represents the total number of deleted documents.

Examples:

In the following examples, we are working with:

Database: GeeksforGeeks
Collection: contributor
Document: four documents that contain the details of the contributors in the form of field-value pairs.

Deleting documents that matches the filter:

In this example, we are deleting multiple documents from the contributor collection that matches the filter, i.e., language: “C#”. Or in other words, we are removing those contributors who are working with C# language from the database.

Deleting all documents:

In this example, we are deleting all the documents from the contributor collection by passing empty document in the db.collection.deleteMany() method.

db.contributor.deleteMany({})

Attention reader! Don’t stop learning now. Get hold of all the important CS Theory concepts for SDE interviews with the CS Theory Course at a student-friendly price and become industry ready.