MongoDB Remove() Method – db.Collection.remove()

The remove() method removes documents from the database. It can remove one or all documents from the collection that matches the given query expression. If you pass an empty document({}) in this method, then it will remove all documents from the specified collection. It takes four parameters and returns an object that contains the status of the operation.

• This method uses the default write concern because it uses the delete command and the delete command uses the default write concern. So, if you want to specify a different write concern, then include the write concern in the optional parameter.
• As we know that, this method removes all the documents that match the given matching_criteria, but we want to remove only one document. So, for this situation set the value of justOne option to true to remove only one document.
• You cannot remove capped collections using the remove() method.
• This method can also be used inside a multi-document transaction.
• All the remove() method operations perform for the shared collection that specifies the justOne: true option must contain the shared key/_id field in the query specification. If not then this operation will return error.

Syntax:

db.Collection_name.remove(

<matching_criteria>,

{

    justOne: <boolean>,

    writeConcern: <document>,

    collation: <document>

})

Parameter:

This parameter specifies deletion criteria using query operators. To remove all the documents from the collection, pass an empty document ({}).

Optional Parameters:

• justOne: Its default value is false that deletes all documents according to matching criteria. Set to true if you want to delete only one document.
• writeConcern: It is only used when you do not want to use the default write concern. The type of this parameter is a 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 a document.

Returns:

This method returns an object that contains the status of the operation.

Examples:

In the following examples, we are working with:

Database: gfg

Collections: student

Document: Three documents contains name and the age of the students

Example 1: Remove all the documents that match the given condition

db.student.remove({name: "Akshay"})

Here, we remove all the documents from the student collection that matches the given condition, i.e, name: “Akshay”.

Example 2: Remove all the documents

db.student.remove({})

Here, we remove all the documents from the student collection by passing empty document(i.e., {}) in the remove() method.

Example 3: Remove only single document

db.student.remove({age:{$eq:18}}, true)

Here, two documents matched the specified condition, but we only want to remove one document, so we set the value of justOne option to true.