db.collection.remove()

Write Concern

The remove() method uses the delete command, which uses the default write concern. To specify a different write concern, include the write concern in the options parameter.

Query Considerations

By default, remove() removes all documents that match the query expression. Specify the justOne option to limit the operation to removing a single document. To delete a single document sorted by a specified order, use the findAndModify() method.

When removing multiple documents, the remove operation may interleave with other read and/or write operations to the collection.

Time Series Collections

You cannot use the remove() method on a time series collection.

Sharded Collections

To use remove() operations for a sharded collection that specify the justOne: true option:

• 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.remove() 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.

Remove All Documents from a Collection

To remove all documents in a collection, call the remove method with an empty query document {}. The following operation deletes all documents from the bios collection:

db.bios.remove( { } )

This operation is not equivalent to the drop() method.

To remove all documents from a collection, it may be more efficient to use the drop() method to drop the entire collection, including the indexes, and then recreate the collection and rebuild the indexes.

Remove All Documents that Match a Condition

To remove the documents that match a deletion criteria, call the remove() method with the <query> parameter:

The following operation removes all the documents from the collection products where qty is greater than 20:

db.products.remove( { qty: { $gt: 20 } } )

Override Default Write Concern

The following operation to a replica set removes all the documents from the collection products where qty is greater than 20 and specifies a write concern of w: 2 with a wtimeout of 5000 milliseconds. This operation either returns after the write propagates to both the primary and one secondary, or times out after 5 seconds.

db.products.remove(
    { qty: { $gt: 20 } },
    { writeConcern: { w: "majority", wtimeout: 5000 } }
)

Remove a Single Document that Matches a Condition

To remove the first document that match a deletion criteria, call the remove method with the query criteria and the justOne parameter set to true or 1.

The following operation removes the first document from the collection products where qty is greater than 20:

db.products.remove( { qty: { $gt: 20 } }, true )

Specify Collation

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

Use Variables in let

To define variables that you can access elsewhere in the command, use the let option.

Create a collection cakeFlavors:

db.cakeFlavors.insertMany( [
   { _id: 1, flavor: "chocolate" },
   { _id: 2, flavor: "strawberry" },
   { _id: 3, flavor: "cherry" }
] )

The following example defines a targetFlavor variable in let and uses the variable to delete the strawberry cake flavor:

db.cakeFlavors.remove(
   { $expr: { $eq: [ "$flavor", "$$targetFlavor" ] } },
   { let : { targetFlavor: "strawberry" } }
)

Successful Results

The remove() returns a WriteResult() object that contains the status of the operation. Upon success, the WriteResult() object contains information on the number of documents removed:

WriteResult({ "nRemoved" : 4 })

Write Concern Errors

If the remove() method encounters write concern errors, the results include the WriteResult.writeConcernError field:

WriteResult({
  "nRemoved" : 7,
  "writeConcernError" : {
    "code" : 64,
    "codeName" : "WriteConcernFailed",
    "errmsg" : "waiting for replication timed out",
    "errInfo" : {
      "wtimeout" : true,
      "writeConcern" : {
        "w" : "majority",
        "wtimeout" : 1,
        "provenance" : "getLastErrorDefaults"
      }
    }
  }
})

Errors Unrelated to Write Concern

If the remove() method encounters a non-write concern error, the results include WriteResult.writeError field:

WriteResult({
   "nRemoved" : 0,
   "writeError" : {
      "code" : 2,
      "errmsg" : "unknown top level operator: $invalidFieldName"
   }
})