mongosh method. This is not
the documentation for a language-specific driver, such as Node.js.For MongoDB API drivers, refer to the language-specific 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, see Unsupported 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
Behavior
comment() associates a comment string with the
find operation. This can make it easier to track a particular query in the
following diagnostic outputs:
The
system.profileThe configure log verbosity for the
mongodlog, the Database Profiler tutorial, or thedb.currentOp()command.
Example
The following operation attaches a comment to a query on the restaurants
collection:
db.restaurants.find( { "borough" : "Manhattan" } ).comment( "Find all Manhattan restaurants" )
Output Examples
system.profile
The following is an excerpt from the
system.profile:
{ "op" : "query", "ns" : "guidebook.restaurant", "query" : { "find" : "restaurant", "filter" : { "borough" : "Manhattan" }, "comment" : "Find all Manhattan restaurants" }, ... }
mongod log
The following is an excerpt from the mongod log. It has been
formatted for readability.
Important
The verbosity level for QUERY must be greater than 0.
See Configure Log Verbosity Levels
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" } ...
db.currentOp()
Suppose the following operation is currently running on a mongod
instance:
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 }