Delete Single Document in MongoDB Using MongoShell

deleteOne method is used to delete a single document in MongoDB. This method deletes a single existing document from the collection that matches the specified filter. This method can be used in multi-document transactions.

It deletes the first document that matches the condition if multiple documents satisfy the condition.

Note: MongoDB deleteOne method throws an exception when used in a capped collection.

Syntax

db.collection.deleteOne(
    <filter>,
   {
     writeConcern: <document>,
     collation: <document>,
     hint: <document|string>        // Available starting in MongoDB 4.4
   }
)

Parameters:

filter: It specifies the selection criteria for the delete using query operators. If it contains empty document, i.e, {}, then this method will delete the first document 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.
• hint:  It specifies the index to use to support the filter query

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.

How to Delete Single Document in MongoDB Collection Examples

Let’s look at some examples, that explains how users can delete a single document from a collection in MongoDB. We will cover different use cases of deleteOne method to delete single document from a collection.

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 the First Document from Collection Example

In this example, we are deleting first document from the contributor collection.

db.contributor.deleteOne({})

Deleting a Single Document That Matches the Filter Example

In this example, we are deleting a single document that matches the filter, i.e., name: “Somya” from the contributor collection.

Delete Single Document When Multiple Document Match Filter Example

In this example, we are deleting a document from the contributor collection. Here two document matches the filter(i.e., language: “C#”), so this method will delete the first document that matches the filter among these two documents.

Conclusion

In this guide, we have learnt how to delete a single document from a collection in MongoDB using MongoShell. Using MongoDB’s deleteOne method, we can restrict the delete operation to single document, ensuring precise deletion.

We have also seen different use cases of this method, to understand it’s complete working and avoid making mistakes.