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db.collection.deleteOne()

Definition

db.collection.deleteOne()

Removes a single document from a collection.

db.collection.deleteOne(
   <filter>,
   {
      writeConcern: <document>,
      collation: <document>
   }
)
Parameter Type Description
filter document

Specifies deletion criteria using query operators.

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.
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.

New in version 3.4.

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

Behavior

Deletion Order

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.

Capped Collections

deleteOne() throws a WriteError exception if used on a capped collection. To remove documents from a capped collection, use db.collection.drop() instead.

Examples

Delete a Single Document

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 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 acknowledgement takes longer than the wtimeout limit, the following exception is thrown:

WriteConcernError({
   "code" : 64,
   "errInfo" : {
      "wtimeout" : true
   },
   "errmsg" : "waiting for replication timed out"
})

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.deleteOne(
   { category: "cafe", status: "A" },
   { collation: { locale: "fr", strength: 1 } }
)

See also

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