cursor.comment()
Definition
mongo
Shell Method
This page documents the mongo
shell method, and doesnot refer to the MongoDB Node.js driver (or any other driver)method. For corresponding MongoDB driver API, refer to your specificMongoDB driver documentation instead.
New in version 3.2.
Adds a comment
field to the query.
cursor.comment()
has the following syntax:
- cursor.comment( <string> )
comment()
has the following parameter:
ParameterTypeDescriptioncomment
stringThe comment to apply to the query.
Behavior
comment()
associates a comment string with thefind operation. This can make it easier to track a particular query in thefollowing diagnostic outputs:
- The
system.profile
- The
QUERY
log component db.currentOp()
See configure log verbosity for themongod
log, theDatabase Profiler tutorial, orthe db.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 thesystem.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 beenformatted for readability.
Important
The verbosity level for QUERY
must be greater than 0
.See Configure Log Verbosity Levels
- 2015-11-23T13:09:16.202-0500 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
- }