Docs Menu
Docs Home
/
MongoDB Manual
/
Change Streams
/
Change Events

insert

On this page

  • Summary
  • Description
  • Example

Summary

insert

An insert event occurs when an operation adds documents to a collection.

Description

Field
Type
Description

_id

Document

A BSON object which serves as an identifier for the change stream event. This value is used as the resumeToken for the resumeAfter parameter when resuming a change stream. The _id object has the following form:

{
   "_data" : <BinData|hex string>
}

The _data type depends on the MongoDB versions and, in some cases, the feature compatibility version (fCV) at the time of the change stream's opening or resumption. See Resume Tokens for the full list of _data types.

For an example of resuming a change stream by resumeToken, see Resume a Change Stream.

clusterTime

Timestamp

clusterTime is the timestamp from the oplog entry associated with the event.

Due to oplog size limits, multi-document transactions may create multiple oplog entries. In a transaction, change stream events staged in a given oplog entry share the same clusterTime.

On sharded clusters, events with the same clusterTime may not all relate to the same transaction. Some events don't relate to a transaction at all.

To identify events for a single transaction, you can use the combination of lsid and txnNumber in the change stream event document.

documentKey

document

Document that contains the _id value of the document created or modified by the CRUD operation.

For sharded collections, this field also displays the full shard key for the document. The _id field is not repeated if it is already a part of the shard key.

fullDocument

document

The document created by the operation.

lsid

document

The identifier for the session associated with the transaction.

Only present if the operation is part of a multi-document transaction.

ns

document

The namespace (database and or collection) affected by the event.

ns.coll

string

The name of the collection where the event occurred.

ns.db

string

The name of the database where the event occurred.

operationType

string

The type of operation that the change notification reports.

Returns a value of insert for these change events.

txnNumber

NumberLong

Together with the lsid, a number that helps uniquely identify a transction.

Only present if the operation is part of a multi-document transaction.

Example

The following example illustrates an insert event:

{
   "_id": { <Resume Token> },
   "operationType": "insert",
   "clusterTime": <Timestamp>,
   "ns": {
      "db": "engineering",
      "coll": "users"
   },
   "documentKey": {
      "userName": "alice123",
      "_id": ObjectId("599af247bb69cd89961c986d")
   },
   "fullDocument": {
      "_id": ObjectId("599af247bb69cd89961c986d"),
      "userName": "alice123",
      "name": "Alice"
   }
}

The documentKey field includes both the _id and the userName field. This indicates that the engineering.users collection is sharded, with a shard key on userName and _id.

The fullDocument document represents the version of the document at the time of the insert.

Back

dropDatabase

Next

invalidate