delete

Definition

delete

The delete command removes documents from a collection. A single delete command can contain multiple delete specifications. The command cannot operate on capped collections. The remove methods provided by the MongoDB drivers use this command internally.

Tip

In the mongo Shell, this command can also be run through the deleteOne(), deleteMany(), and findOneAndDelete() helper methods.

Helper methods are convenient for mongo users, but they may not return the same level of information as database commands. In cases where the convenience is not needed or the additional return fields are required, use the database command.

The delete command has the following syntax:

{
   delete: <collection>,
   deletes: [
      {
        q : <query>,
        limit : <integer>,
        collation: <document>,
        hint: <document|string>
      },
      ...
   ],
   comment: <any>,
   ordered: <boolean>,
   writeConcern: { <write concern> },
   maxTimeMS: <integer>
}

The command takes the following fields:

Field	Type	Description
delete	string	The name of the target collection.
deletes	array	An array of one or more delete statements to perform in the named collection.
comment	any	Optional. A user-provided comment to attach to this command. Once set, this comment appears alongside records of this command in the following locations: mongod log messages, in the attr.command.cursor.comment field. Database profiler output, in the command.comment field. currentOp output, in the command.comment field. A comment can be any valid BSON type (string, integer, object, array, etc). New in version 4.4.
ordered	boolean	Optional. If true, then when a delete statement fails, return without performing the remaining delete statements. If false, then when a delete statement fails, continue with the remaining delete statements, if any. Defaults to true.
writeConcern	document	Optional. A document expressing the write concern of the delete command. 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.
maxTimeMS	non-negative integer	Optional. Specifies a time limit in milliseconds. If you do not specify a value for maxTimeMS, operations will not time out. A value of 0 explicitly specifies the default unbounded behavior. MongoDB terminates operations that exceed their allotted time limit using the same mechanism as db.killOp(). MongoDB only terminates an operation at one of its designated interrupt points.

Each element of the deletes array contains the following fields:

Field	Type	Description
q	document	The query that matches documents to delete.
limit	integer	The number of matching documents to delete. Specify either a 0 to delete all matching documents or 1 to delete a single document.
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. New in version 3.4.
hint	Document or string	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. New in version 4.4.

Returns:	A document that contains the status of the operation. See Output for details.

Behavior

Examples

db.runCommand(
   {
      delete: "orders",
      deletes: [ { q: { status: "D" }, limit: 1 } ]
   }
)

{ "ok" : 1, "n" : 1 }

db.runCommand(
   {
      delete: "orders",
      deletes: [ { q: { status: "D" }, limit: 0 } ],
      writeConcern: { w: "majority", wtimeout: 5000 }
   }
)

{ "ok" : 1, "n" : 13 }

db.runCommand(
   {
      delete: "orders",
      deletes: [ { q: { }, limit: 0 } ],
      writeConcern: { w: "majority", wtimeout: 5000 }
   }
)

{ "ok" : 1, "n" : 35 }

db.runCommand(
   {
      delete: "orders",
      deletes: [
         { q: { status: "D" }, limit: 0 },
         { q: { cust_num: 99999, item: "abc123", status: "A" }, limit: 1 }
      ],
      ordered: false,
      writeConcern: { w: 1 }
   }
)

{ "ok" : 1, "n" : 21 }

{ _id: 1, category: "café", status: "A" }
{ _id: 2, category: "cafe", status: "a" }
{ _id: 3, category: "cafE", status: "a" }

db.runCommand({
   delete: "myColl",
   deletes: [
     { q: { category: "cafe", status: "a" }, limit: 0, collation: { locale: "fr", strength: 1 } }
   ]
})

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" }
])

db.members.createIndex( { status: 1 } )
db.members.createIndex( { points: 1 } )

db.runCommand({
   delete: "members",
   deletes: [
     { q: { "points": { $lte: 20 }, "status": "P" }, limit: 0, hint: { status: 1 } }
   ]
})

db.runCommand(
   {
     explain: {
       delete: "members",
       deletes: [
         { q: { "points": { $lte: 20 }, "status": "P" }, limit: 0, hint: { status: 1 } }
       ]
     },
     verbosity: "queryPlanner"
   }
)

Output

The returned document contains a subset of the following fields:

delete.ok

The status of the command.

delete.n

The number of documents deleted.

delete.writeErrors

An array of documents that contains information regarding any error encountered during the delete operation. The writeErrors array contains an error document for each delete statement that errors.

Each error document contains the following information:

delete.writeErrors.index

An integer that identifies the delete statement in the deletes array, which uses a zero-based index.

delete.writeErrors.code

An integer value identifying the error.

delete.writeErrors.errmsg

A description of the error.

delete.writeConcernError

Document that describe error related to write concern and contains the fields:

delete.writeConcernError.code

An integer value identifying the cause of the write concern error.

delete.writeConcernError.errmsg

A description of the cause of the write concern error.

delete.writeConcernError.errInfo.writeConcern

New in version 4.4.

The write concern object used for the corresponding operation. For information on write concern object fields, see Write Concern Specification.

The write concern object may also contain the following field, indicating the source of the write concern:

delete.writeConcernError.errInfo.writeConcern.provenance

A string value indicating where the write concern originated (known as write concern provenance). The following table shows the possible values for this field and their significance:

Provenance	Description
clientSupplied	The write concern was specified in the application.
customDefault	The write concern originated from a custom defined default value. See setDefaultRWConcern.
getLastErrorDefaults	The write concern originated from the replica set's settings.getLastErrorDefaults field.
implicitDefault	The write concern originated from the server in absence of all other write concern specifications.

The following is an example document returned for a successful delete command:

{ ok: 1, n: 1 }

The following is an example document returned for a delete command that encountered an error:

{
   "ok" : 1,
   "n" : 0,
   "writeErrors" : [
      {
         "index" : 0,
         "code" : 10101,
         "errmsg" : "can't remove from a capped collection: test.cappedLog"
      }
   ]
}