cursor.showRecordId()
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cursor.showRecordId()
Important
mongosh Method
This is a
mongosh
method. This is not the documentation forNode.js
or other programming language specific driver methods.In most cases,
mongosh
methods work the same way as the legacymongo
shell methods. However, some legacy methods are unavailable inmongosh
.For the legacy
mongo
shell documentation, refer to the documentation for the corresponding MongoDB Server release:For MongoDB API drivers, refer to the language specific MongoDB driver documentation.
Changed in version 3.2: This method replaces the previous
cursor.showDiskLoc()
.Modifies the output of a query by adding a field
$recordId
to matching documents.$recordId
is the internal key which uniquely identifies a document in a collection. It has the form:"$recordId": NumberLong(<int>) Returns: A modified cursor object that contains documents with appended information describing the internal record key.
Example
The following operation appends the showRecordId()
method to the db.collection.find()
method in order to include
storage engine record information in the matching documents:
db.collection.find( { a: 1 } ).showRecordId()
The operation returns the following documents, which include the $recordId
field:
{ "_id" : ObjectId("53908ccb18facd50a75bfbac"), "a" : 1, "b" : 1, "$recordId" : NumberLong(168112) } { "_id" : ObjectId("53908cd518facd50a75bfbad"), "a" : 1, "b" : 2, "$recordId" : NumberLong(168176) }
You can project the added field $recordId
, as in the
following example:
db.collection.find( { a: 1 }, { $recordId: 1 } ).showRecordId()
This query returns only the _id
field and the $recordId
field in the matching documents:
{ "_id" : ObjectId("53908ccb18facd50a75bfbac"), "$recordId" : NumberLong(168112) } { "_id" : ObjectId("53908cd518facd50a75bfbad"), "$recordId" : NumberLong(168176) }