cursor.comment() (original) (raw)

cursor.comment()

Important

mongosh Method

This page documents a mongosh method. This is _not_the documentation for a language-specific driver, such as Node.js.

For MongoDB API drivers, refer to the language-specificMongoDB driver documentation.

Adds a comment field to the query.

cursor.comment() has the following syntax:


cursor.comment( <string> )

comment() has the following parameter:

Parameter	Type	Description
comment	string	The comment to apply to the query.

This method is available in deployments hosted in the following environments:

MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud

Note

This command is supported in all MongoDB Atlas clusters. For information on Atlas support for all commands, seeUnsupported Commands.

MongoDB Enterprise: The subscription-based, self-managed version of MongoDB
MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB

comment() associates a comment string with the find operation. This can make it easier to track a particular query in the following diagnostic outputs:

See configure log verbosity for themongod log, theDatabase Profiler tutorial, or the db.currentOp() command.

The following operation attaches a comment to a query on the restaurantscollection:


db.restaurants.find(

   { "borough" : "Manhattan" }

).comment( "Find all Manhattan restaurants" )

The following is an excerpt from thesystem.profile:


{

   "op" : "query",

   "ns" : "guidebook.restaurant",

   "query" : {

      "find" : "restaurant",

      "filter" : {

         "borough" : "Manhattan"

      },

      "comment" : "Find all Manhattan restaurants"

   },

   ...

}

The following is an excerpt from the mongod log. It has been formatted for readability.

Important


2015-11-23T13:09:16.202-05:00 I COMMAND  [conn1]

   command guidebook.restaurant command: find {

      find: "restaurant",

      filter: { "borough" : "Manhattan" },

      comment: "Find all Manhattan restaurants"

   }

   ...

Suppose the following operation is currently running on a mongodinstance:


db.restaurants.find(

   { "borough" : "Manhattan" }

).comment("Find all Manhattan restaurants")

Running the db.currentOp() command returns the following:


{

   "inprog" : [

      {

         "host" : "198.51.100.1:27017",

         "desc" : "conn3",

         "connectionId" : 3,

         ...

         "op" : "query",

         "ns" : "test.$cmd",

         "command" : {

            "find" : "restaurants",

            "filter" : {

               "borough" : "Manhattan"

            },

            "comment" : "Find all Manhattan restaurants",

            "$db" : "test"

         },

         "numYields" : 0,

         ...

      }

   ],

   "ok" : 1

}