db.collection.deleteMany()
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Definition
db.collection.deleteMany()
Important
mongo Shell Method
This page documents a
mongo
method. This is not the documentation for database commands or language-specific drivers, such as Node.js. To use the database command, see thedelete
command.For MongoDB API drivers, refer to the language-specific MongoDB driver documentation.
Removes all documents that match the
filter
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
You can use db.collection.deleteMany()
for deployments hosted in the following
environments:
MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud
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 deleteMany()
method has the following
syntax:
db.collection.deleteMany( <filter>, { writeConcern: <document>, collation: <document> } )
Parameter | Type | Description | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
document | Specifies deletion criteria using query operators. To delete all documents in a collection, pass in 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. New in version 3.4. | |||||||||||
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 New in version 4.4. |
Behavior
Capped Collections
db.collection.deleteMany()
throws a WriteError
exception
if used on a capped collection. To remove all documents from a capped
collection, use db.collection.drop()
instead.
Delete a Single Document
To delete a single document, use db.collection.deleteOne()
instead.
Alternatively, use a field that is a part of a unique index such as
_id
.
Transactions
db.collection.deleteMany()
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.
Primary Node Failure
db.collection.deleteMany()
deletes documents one at a time.
If the primary node fails during a db.collection.deleteMany()
operation, documents that were not yet deleted from secondary nodes are
not deleted from the collection.
Examples
Delete Multiple Documents
The orders
collection has documents with the following structure:
{ _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 all documents where client : "Crude Traders
Inc."
:
try { db.orders.deleteMany( { "client" : "Crude Traders Inc." } ); } catch (e) { print (e); }
The operation returns:
{ "acknowledged" : true, "deletedCount" : 10 }
The following operation deletes all documents where stock : "Brent Crude
Futures"
and limit
is greater than 48.88
:
try { db.orders.deleteMany( { "stock" : "Brent Crude Futures", "limit" : { $gt : 48.88 } } ); } catch (e) { print (e); }
The operation returns:
{ "acknowledged" : true, "deletedCount" : 8 }
deleteMany() with Write Concern
Given a three member replica set, the following operation specifies a
w
of majority
and wtimeout
of 100
:
try { db.orders.deleteMany( { "client" : "Crude Traders Inc." }, { writeConcern: { w : "majority", wtimeout : 100 }} ); } catch (e) { print (e); }
If the acknowledgement takes longer than the wtimeout
limit, the following
exception is thrown:
WriteConcernError({ "code" : 64, "errmsg" : "waiting for replication timed out", "errInfo" : { "wtimeout" : true, "writeConcern" : { // Added in MongoDB 4.4 "w" : "majority", "wtimeout" : 100, "provenance" : "getLastErrorDefaults" } } })
Specify Collation
New in version 3.4.
Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.
A collection myColl
has the following documents:
{ _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.myColl.deleteMany( { category: "cafe", status: "A" }, { collation: { locale: "fr", strength: 1 } } )
Specify hint
for Delete Operations
New in version 4.4.
From the mongo
shell, create a members
collection
with the following documents:
db.members.insertMany([ { "_id" : 1, "member" : "abc123", "status" : "P", "points" : 0, "misc1" : null, "misc2" : null }, { "_id" : 2, "member" : "xyz123", "status" : "A", "points" : 60, "misc1" : "reminder: ping me at 100pts", "misc2" : "Some random comment" }, { "_id" : 3, "member" : "lmn123", "status" : "P", "points" : 0, "misc1" : null, "misc2" : null }, { "_id" : 4, "member" : "pqr123", "status" : "D", "points" : 20, "misc1" : "Deactivated", "misc2" : null }, { "_id" : 5, "member" : "ijk123", "status" : "P", "points" : 0, "misc1" : null, "misc2" : null }, { "_id" : 6, "member" : "cde123", "status" : "A", "points" : 86, "misc1" : "reminder: ping me at 100pts", "misc2" : "Some random comment" } ])
Create the following indexes on the collection:
db.members.createIndex( { status: 1 } ) db.members.createIndex( { points: 1 } )
The following delete operation explicitly hints to use the index
{ status: 1 }
:
db.members.deleteMany( { "points": { $lte: 20 }, "status": "P" }, { hint: { status: 1 } } )
Note
If you specify an index that does not exist, the operation errors.
The delete command returns the following:
{ "acknowledged" : true, "deletedCount" : 3 }
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.