Judging by [Jira][1] they have done it: You need to write `cls` in the shell.

You can also use a hotkey: &lt;kbd&gt;CTRL&lt;/kbd&gt; + &lt;kbd&gt;L&lt;/kbd&gt;.

In macOS: &lt;kbd&gt;Command&lt;/kbd&gt; + &lt;kbd&gt;K&lt;/kbd&gt;.

Check more hotkeys for the shell [here][2].


  [1]: https://jira.mongodb.org/browse/SERVER-2533?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
  [2]: http://docs.mongodb.org/manual/reference/mongo-shell/#keyboard-shortcuts

If you are using MongoDB 2.0 or higher, the `mongo` shell supports both:

 * `cls` command
 * `Ctrl+l` (clear screen)

Note that both of these clear the screen and put the cursor at the top .. but you can still scrollback to see previous history.

In OS X Terminal.app you can also do:

 * `Command+K` (clear scrollback)

Clearing the screen and/or scrollback buffer are independent of the history, so you can still cursor up/down to run previous commands.

I want to inspect my website CSS/HTML elements in my Android browser.

However it will be over a smartphone or the Android SDK. 

What is the best way to do it?

How can I inspect element in an Android browser?

I want to know what are difference(s) between `vector`&#39;s `push_back` and `insert` functions.

Is there a structural difference(s)?

Is there a really big performance difference(s)?

C++ vector&#39;s insert &amp; push_back difference

While using Mongodb console or shell sometimes my screen is cluttered with a lot of previous output which I do not need. So, is there a function to clear console in MongoDB?



Something like an analog of clear in MatLab.

I have tried `clc`, `clear` but with no success.

How to clear console in MongoDB

While using Mongodb console or shell sometimes my screen is cluttered with a lot of previous output which I do not need. So, is there a function to clear console in MongoDB?
Something like an analog of clear in MatLab.
I have tried <code>clc</code>, <code>clear</code> but with no success.

I am using Flask and MongoDB. I am trying to convert the content of request.form into something suitable for saving via PyMongo. It seems like something that should come up often enough to have a ready-made solution.

So what Flask give me is something like:

    ImmutableMultiDict([(&#39;default&#39;, u&#39;&#39;), (&#39;required&#39;: u&#39;on&#39;), (&#39;name&#39;, u&#39;short_text&#39;), (&#39;name&#39;, u&#39;another&#39;), (&#39;submit&#39;, u&#39;Submit&#39;)])

And what I am looking to get is something close to this:

    {
      &#39;default&#39;: &#39;&#39;,
      &#39;name&#39;: [&#39;short_text&#39;, &#39;another&#39;],
      &#39;required&#39;: true
    }


In Flask convert form POST object into a representation suitable for mongodb

I cannot manually or automatically populate the creator field on a newly saved object ... the only way I can find is to re-query for the objects I already have which I would hate to do.

This is the setup:

    var userSchema = new mongoose.Schema({   
      name: String,
    });
    var User = db.model(&#39;User&#39;, userSchema);

    var bookSchema = new mongoose.Schema({
      _creator: { type: mongoose.Schema.Types.ObjectId, ref: &#39;User&#39; },
      description: String,
    });
    var Book = db.model(&#39;Book&#39;, bookSchema);

This is where I am pulling my hair

    var user = new User();
    user.save(function(err) {
        var book = new Book({
            _creator: user,
        });
        book.save(function(err){
            console.log(book._creator); // is just an object id
            book._creator = user; // still only attaches the object id due to Mongoose magic
            console.log(book._creator); // Again: is just an object id
            // I really want book._creator to be a user without having to go back to the db ... any suggestions?
        });
    });

EDIT: latest mongoose fixed this issue and added populate functionality, see the new accepted answer.

Mongoose populate after save

I have a mongo document like this.

	{
	    &quot;_id&quot; : ObjectId(&quot;50b429ba0e27b508d854483e&quot;),
	    &quot;array&quot; : [
	        {
	            &quot;id&quot; : &quot;1&quot;,
	            &quot;letter&quot; : &quot;a&quot;
	        },
	        {
	            &quot;id&quot; : &quot;2&quot;,
	            &quot;letter&quot; : &quot;b&quot;
	        }
	    ],
	    &quot;tester&quot; : &quot;tom&quot;
	}
	
I want to be able to insert and update the `array` with a single mongo command and not use a conditional within a `find()` then run `insert()` and `update()` depending on the presence of the object.

The `id` is the item I want to be the selector. So if I update the array with this:

	{
	    &quot;id&quot; : &quot;2&quot;,
	    &quot;letter&quot; : &quot;c&quot;
	}

I have to use a `$set` statement

	db.soup.update({
		&quot;tester&quot;:&quot;tom&quot;,
	    &#39;array.id&#39;: &#39;2&#39;
	}, {
	    $set: {
	        &#39;array.$.letter&#39;: &#39;c&#39;
	    }
	})
	
And if I want to insert a new object into the array

	{
	    &quot;id&quot; : &quot;3&quot;,
	    &quot;letter&quot; : &quot;d&quot;
	}
	
I have to use a `$push` statement

	db.soup.update({
		&quot;tester&quot;:&quot;tom&quot;
	}, {
	    $push: {
	        &#39;array&#39;: {
	            &quot;id&quot;: &quot;3&quot;,
	            &quot;letter&quot;: &quot;d&quot;
	        }
	    }
	})
	
I need a sort of upsert for an array item. 

Do I have to do this programmatically or can I do this with a single mongo call?

Can mongo upsert array data?

My Ubuntu computer had crashed, and when I restarted it MongoDB wasn&#39;t working. I tried the following commands, and got the following output:

    $ mongo
    Error: couldn&#39;t connect to server 127.0.0.1:27017 src/mongo/shell/mongo.js:91
    exception: connect failed

    $ service mongodb status
    mongodb stop/waiting

    $ service mongodb restart
    stop: Unknown instance: 
    start: Rejected send message, 1 matched rules; type=&quot;method_call&quot;,
           sender=&quot;:1.57&quot; (uid=1000 pid=2227 comm=&quot;start mongodb &quot;)
           interface=&quot;com.ubuntu.Upstart0_6.Job&quot; member=&quot;Start&quot; error name=&quot;(unset)&quot;
           requested_reply=&quot;0&quot;
           destination=&quot;com.ubuntu.Upstart&quot; (uid=0 pid=1 comm=&quot;/sbin/init&quot;)

    $ tail /var/log/mongodb/mongodb.log
    [initandlisten] exception in initAndListen: 12596 old lock file, terminating
    dbexit: 
    [initandlisten] shutdown: going to close listening sockets...
    [initandlisten] shutdown: going to flush diaglog...
    [initandlisten] shutdown: going to close sockets...
    [initandlisten] shutdown: waiting for fs preallocator...
    [initandlisten] shutdown: closing all files...
    [initandlisten] closeAllFiles() finished
    dbexit: really exiting now


(Output reformatted to match website layout.)

What happened? How can I fix it?

MongoDB won&#39;t start after server crash

I&#39;ve a mongodb collection in this form:

    {id=ObjectId(....),key={dictionary of values}}
    where dictionary of values is {&#39;a&#39;:&#39;1&#39;,&#39;b&#39;:&#39;2&#39;.....}
Let dictionary of values be `&#39;d&#39;`.
I need to update the values of the key in the `&#39;d&#39;`.
i.e I want to change `&#39;a&#39;:&#39;1&#39;` to `&#39;a&#39;:&#39;2&#39;`
How can do I this in pymongo?

Code goes something like this:

    productData is a collection in mongoDB
    for p in productData.find():
         for k,v in p.iteritems():
             value=v[&#39;a&#39;]
             value=value+1
             v[&#39;a&#39;]=value
            
 Now reflect the new value in the productData.   


This is what I&#39;ve tried and it introduces a new key-value pair instead of updating the        

    for p in productData.find():
        for k,v in p.iteritems():
             value=v[&#39;a&#39;]
             value=value+1
             v[&#39;a&#39;]=value
             productData.update({&#39;_id&#39;:mongoId},{&quot;$set&quot;:{&#39;d.a&#39;:&#39;100&#39;}},upsert=False)



How to update values using pymongo?

If I&#39;m writing an application which connects to mongodb then I can provide a seed list for a replicaset, and the driver will direct me to the master node, where I can run write commands.

How do I specify the seed list for a commandline `mongo` shell in order to conenct to a replicaset.

How do you connect to a replicaset from a MongoDB shell?

I have mongo DB installed in the following path `c:\mongodb\bin`. I have configured my environment variable PATH in advanced settings.I also have mongod running .When I run the following command **mongorestore dump** from the following path `c:\hw1-1\dump` (This contains the BSON files) I&#39;m getting this error:

&gt; Don&#39;t know what to do with the dump file

I have referred to [this thread](https://education.mongodb.com/courses/10gen/M101JS/2014_January/discussion/forum/i4x-10gen-M101JS-course-2014_January/threads/52d7b1cdabcee8bd1e006540) to check my path.

mongorestore error: Don&#39;t know what to do with the dump file

2 days old with Mongo and I have a SQL background so bear with me. As with mysql, it is very convenient to be in the MySQL command line and output the results of a query to a file on the machine. I am trying to understand how I can do the same with Mongo, **while being in the shell**

I can easily get the output of a query I want by being outside of the shell and executing the following command:

    mongo localhost:27017/dbname --eval &quot;printjson(db.collectionName.findOne())&quot; &gt; sample.json

The above way is fine, but it requires me to exit the mongo shell or open a new terminal tab to execute this command. It would be very convenient if I could simply do this while still being inside the shell. 

P.S: the Question is an offshoot of a question I posted on [SO][1] 


  [1]: https://stackoverflow.com/questions/22540405/syntax-error-missingl-before-statement-while-outputting-mongodb-query-to-a-text/22541861#22541861

Printing Mongo query output to a file while in the mongo shell

I would like to drop into the mongo shell in the terminal on my MacBook.  However, I&#39;m interested in connecting to a Mongo instance that is running in the cloud (compose.io instance via Heroku addon).  I have the name, password, host, port, and database name from the MongoDB URI:

    mongodb://username:password@somewhere.mongolayer.com:10011/my_database

I have installed mongodb on my MacBook using Homebrew not because I want Mongo running on my Mac, but just to get access to the mongo shell program in order to connect to this remote database.

However, I can&#39;t find the right command to get me the full shell access I would like.  Using instructions found here http://docs.mongodb.org/manual/reference/program/mongo/ (search for &quot;remote&quot;) I am able to get what looks like a connection, but without giving my username or password I am not fully connected.  Running `db.auth(username, password)` returns 1 (as opposed to &quot;auth fails&quot; when I provide incorrect username and password), but I continue to get an &quot;unauthorized&quot; error message when issuing the `show dbs` command.

Content Type	Original Author	Original Content on Stackoverflow
Question	user1015104	View Question on Stackoverflow
Solution 1 - Mongodb	Salvador Dali	View Answer on Stackoverflow
Solution 2 - Mongodb	Stennie	View Answer on Stackoverflow

How to clear console in MongoDB

Mongodb Problem Overview

Mongodb Solutions

Solution 1 - Mongodb

Solution 2 - Mongodb

C++ vector's insert & push_back difference

How can I inspect element in an Android browser?

Attributions