Join us at MongoDB.local London on 7 May to unlock new possibilities for your data. Use WEB50 to save 50%.
Register now >
Docs Menu
Docs Home
/
Development
/
mongosh Methods
Docs Home
/
Development
/
mongosh Methods
Docs Home
/
Development
/
mongosh Methods

db.collection.deleteOne() (mongosh method)

MongoDB with drivers

This page documents a mongosh method. To see the equivalent method in a MongoDB driver, see the corresponding page for your programming language:

C#Java SyncNode.jsPyMongoC++GoJava RSKotlin CoroutineKotlin SyncPHPMongoidRustScala

Definition

db.collection.deleteOne()

Removes a single document from a collection.

Returns:A document containing:

  • A boolean acknowledged as true if the operation ran with write concern or false if write concern was disabled

  • deletedCount containing the number of deleted documents

Compatibility

This method is available in deployments hosted in the following environments:

  • MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud

Note

This command is supported in all MongoDB Atlas clusters. For information on Atlas support for all commands, see Unsupported Commands.

Syntax

The deleteOne() method has the following form:

db.collection.deleteOne(
    <filter>,
    {
      writeConcern: <document>,
      collation: <document>,
      hint: <document|string>,
      maxTimeMS: <int>,
      let: <document>
    }
)

The deleteOne() method takes the following parameters:

Parameter
Type
Description

filter

document

Specifies deletion criteria using a query predicate.

Specify an empty document { } to delete the first document returned in the collection.

writeConcern

document

Optional. A document expressing the write concern. Omit to use the default write concern.

Do not explicitly set the write concern for the operation if run in a transaction. To use write concern with transactions, see Transactions and Write Concern.

collation

document

Optional.

Specifies the collation to use for the operation.

Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.

The collation option has the following syntax:

collation: {
    locale: <string>,
    caseLevel: <boolean>,
    caseFirst: <string>,
    strength: <int>,
    numericOrdering: <boolean>,
    alternate: <string>,
    maxVariable: <string>,
    backwards: <boolean>
 }

When specifying collation, the locale field is mandatory; all other collation fields are optional. For descriptions of the fields, see Collation Document.

If the collation is unspecified but the collection has a default collation (see db.createCollection()), the operation uses the collation specified for the collection.

If no collation is specified for the collection or for the operations, MongoDB uses the simple binary comparison used in prior versions for string comparisons.

You cannot specify multiple collations for an operation. For example, you cannot specify different collations per field, or if performing a find with a sort, you cannot use one collation for the find and another for the sort.

hint

document

Optional. A document or string that specifies the index to use to support the query predicate.

The option can take an index specification document or the index name string.

If you specify an index that does not exist, the operation errors.

For an example, see Specify hint for Delete Operations.

maxTimeMS

integer

Optional. Specifies the time limit in milliseconds for the delete operation to run before timing out.

let

Document

Optional.

Specifies a document with a list of variables. This allows you to improve command readability by separating the variables from the query text.

The document syntax is:

{
  <variable_name_1>: <expression_1>,
  ...,
  <variable_name_n>: <expression_n>
}

The variable is set to the value returned by the expression, and cannot be changed afterwards.

To access the value of a variable in the command, use the double dollar sign prefix ($$) together with your variable name in the form $$<variable_name>. For example: $$targetTotal.

To use a variable to filter results, you must access the variable within the $expr operator.

For a complete example using let and variables, see Update with let Variables.

Behavior

Deletion Order

db.collection.deleteOne() deletes the first document that matches the filter. Use a field that is part of a unique index such as _id for precise deletions.

Sharded Collections

To use db.collection.deleteOne() on a sharded collection:

  • If you only target one shard, you can use a partial shard key in the query specification.

  • You do not need to provide the shard key or _id field in the query specification, because deleteOne() inherently uses a limit of 1.

Transactions

db.collection.deleteOne() can be used inside distributed transactions.

Do not explicitly set the write concern for the operation if run in a transaction. To use write concern with transactions, see Transactions and Write Concern.

Important

In most cases, a distributed transaction incurs a greater performance cost over single document writes, and the availability of distributed transactions should not be a replacement for effective schema design. For many scenarios, the denormalized data model (embedded documents and arrays) will continue to be optimal for your data and use cases. That is, for many scenarios, modeling your data appropriately will minimize the need for distributed transactions.

For additional transactions usage considerations (such as runtime limit and oplog size limit), see also Production Considerations.

Oplog Entries

If a db.collection.deleteOne() operation successfully deletes a document, the operation adds an entry on the oplog (operations log). If the operation fails or does not find a document to delete, the operation does not add an entry on the oplog.

Examples

The examples on this page use data from the sample_mflix sample dataset. For details on how to load this dataset into your self-managed MongoDB deployment, see Load the sample dataset. If you made any modifications to the sample databases, you may need to drop and recreate the databases to run the examples on this page.

Delete a Single Document

The following operation deletes the first document where year is earlier than 1910:

db.movies.deleteOne( { year: { $lt: 1910 } } )
{ acknowledged: true, deletedCount: 1 }

deleteOne() with a Timeout and Query Variables

The following operation deletes the first document where year is earlier than the cutoffYear variable and sets a time limit of 3 seconds:

db.movies.deleteOne(
   { $expr: { $lt: ["$year", "$$cutoffYear"] } },
   {
      let: { cutoffYear: 1910 },
      maxTimeMS: 3000
   }
)
{ acknowledged: true, deletedCount: 1 }

deleteOne() with Write Concern

Given a three member replica set, the following operation specifies a w of majority and wtimeout of 100:

db.movies.deleteOne(
   { title: "A Corner in Wheat" },
   { writeConcern: { w: "majority", wtimeout: 100 } }
)
{ acknowledged: true, deletedCount: 1 }

Specify Collation

Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.

The following operation uses the collation option with English locale and strength: 2, which makes comparisons case-insensitive. The filter title: "the dark knight" matches the document with the title "The Dark Knight" in the collection:

db.movies.deleteOne(
   { title: "the dark knight" },
   { collation: { locale: "en", strength: 2 } }
)
{ acknowledged: true, deletedCount: 1 }

Specify hint for Delete Operations

Create indexes on the rated and metacritic fields:

db.movies.createIndex( { rated: 1 } )
db.movies.createIndex( { metacritic: 1 } )

The following delete operation explicitly hints to use the index { rated: 1 }:

db.movies.deleteOne(
   { metacritic: { $lte: 15 }, rated: "PG" },
   { hint: { rated: 1 } }
)
{ acknowledged: true, deletedCount: 1 }

Note

If you specify an index that does not exist, the operation errors.

To view the indexes used, you can use the $indexStats pipeline:

db.movies.aggregate( [ { $indexStats: { } }, { $sort: { name: 1 } } ] )

The accesses.ops field in the $indexStats output indicates the number of operations that used the index.

Tip

To delete multiple documents, see db.collection.deleteMany()

Back

db.collection.deleteMany

Next

db.collection.distinct

On this page