db.collection.deleteOne()
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Definition
db.collection.deleteOne()
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:Removes a single document from a collection.
Returns: A document containing: A boolean
acknowledged
astrue
if the operation ran with write concern orfalse
if write concern was disableddeletedCount
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.
MongoDB Enterprise: The subscription-based, self-managed version of MongoDB
MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB
Syntax
The deleteOne()
method has the following form:
db.collection.deleteOne( <filter>, { writeConcern: <document>, collation: <document>, hint: <document|string> } )
The deleteOne()
method takes the following
parameters:
Parameter | Type | Description | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
document | Specifies deletion criteria using query operators. Specify an empty document | |||||||||||
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. | |||||||||||
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:
When specifying collation, the If the collation is unspecified but the collection has a
default collation (see 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. | |||||||||||
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 |
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 or,
You can provide the shard key or the
_id
field in the query specification.
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
Delete a Single Document
The orders
collection has documents with the following structure:
db.orders.insertOne( { _id: ObjectId("563237a41a4d68582c2509da"), stock: "Brent Crude Futures", qty: 250, type: "buy-limit", limit: 48.90, creationts: ISODate("2015-11-01T12:30:15Z"), expiryts: ISODate("2015-11-01T12:35:15Z"), client: "Crude Traders Inc." } )
The following operation deletes the order with _id:
ObjectId("563237a41a4d68582c2509da")
:
try { db.orders.deleteOne( { _id: ObjectId("563237a41a4d68582c2509da") } ); } catch (e) { print(e); }
The operation returns:
{ acknowledged: true, deletedCount: 1 }
The following operation deletes the first document with expiryts
greater
than ISODate("2015-11-01T12:40:15Z")
try { db.orders.deleteOne( { expiryts: { $lt: ISODate("2015-11-01T12:40:15Z") } } ); } catch (e) { print(e); }
The operation returns:
{ acknowledged: true, deletedCount: 1 }
deleteOne() with Write Concern
Given a three member replica set, the following operation specifies a
w
of majority
, wtimeout
of 100
:
try { db.orders.deleteOne( { _id: ObjectId("563237a41a4d68582c2509da") }, { w: "majority", wtimeout: 100 } ); } catch (e) { print (e); }
If the acknowledgment takes longer than the wtimeout
limit, the following
exception is thrown:
WriteConcernError({ code: 64, errmsg: "waiting for replication timed out", errInfo: { wtimeout: true, writeConcern: { w: "majority", wtimeout: 100, provenance: "getLastErrorDefaults" } } })
Specify Collation
Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.
A collection restaurants
has the following documents:
db.restaurants.insertMany( [ { _id: 1, category: "café", status: "A" }, { _id: 2, category: "cafe", status: "a" }, { _id: 3, category: "cafE", status: "a" } ] )
The following operation includes the collation option:
db.restaurants.deleteOne( { category: "cafe", status: "A" }, { collation: { locale: "fr", strength: 1 } } )
Specify hint
for Delete Operations
In mongosh
, create a students
collection
with the following documents:
db.members.insertMany( [ { _id: 1, student: "Richard", grade: "F", points: 0 }, { _id: 2, student: "Jane", grade: "A", points: 60 }, { _id: 3, student: "Adam", grade: "F", points: 0 }, { _id: 4, student: "Ronan", grade: "D", points: 20 }, { _id: 5, student: "Noah", grade: "F", points: 0 }, { _id: 6, student: "Henry", grade: "A", points: 86 } ] )
Create the following index on the collection:
db.members.createIndex( { grade: 1 } )
The following delete operation explicitly hints to use the index
{ grade: 1 }
:
db.members.deleteOne( { points: { $lte: 20 }, grade: "F" }, { hint: { grade: 1 } } )
Note
If you specify an index that does not exist, the operation errors.
The delete command returns the following:
{ acknowledged: true, deletedCount: 1 }
To view the indexes used, you can use the $indexStats
pipeline:
db.members.aggregate( [ { $indexStats: { } }, { $sort: { name: 1 } } ] )
The accesses.ops
field in the $indexStats
output
indicates the number of operations that used the index.