MongoDB Glossary - Delete Operation

In MongoDB, the delete operation is used to remove documents from a collection. It allows you to delete one or multiple documents that match a specified condition. Understanding how the delete operation works is crucial for effectively managing your MongoDB database.

Delete Methods

MongoDB provides several methods to perform delete operations:

• deleteOne(): Deletes a single document that matches the specified condition.
• deleteMany(): Deletes all documents that match the specified condition.

These methods allow you to delete documents based on specific criteria, such as a field value or a combination of conditions.

Delete Syntax

The basic syntax for the delete operation in MongoDB is as follows:

db.collection.deleteOne(filter, options)
db.collection.deleteMany(filter, options)

The filter parameter specifies the condition that documents must meet to be deleted. It uses the same query syntax as the find operation.

The options parameter is optional and allows you to specify additional settings for the delete operation, such as the maximum number of documents to delete or the write concern.

Delete Examples

Let's consider some examples to illustrate how the delete operation works:

Example 1: Deleting a Single Document

db.users.deleteOne({ name: "John" })

This example deletes a single document from the "users" collection where the name field is equal to "John". If multiple documents match the condition, only the first one encountered will be deleted.

Example 2: Deleting Multiple Documents

db.products.deleteMany({ price: { $lt: 10 } })

This example deletes all documents from the "products" collection where the price field is less than 10. It removes multiple documents that match the condition.

Summary

The delete operation in MongoDB allows you to remove documents from a collection based on specified conditions. MongoDB provides the deleteOne() and deleteMany() methods to perform single and multiple document deletions, respectively. Understanding how to use these methods effectively is essential for managing your MongoDB database efficiently.

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