File write operations in mongo script?

Question

Is this possible to write the query result to the file from mongo js script. I have searched a lot, but I didn\'t find any solution.

ex:-

cursor = db         


        

Answer 1

Whenever I need to write the result of a mongo query to a local file I generally use the the writeFile(pathToFile, stringContents) function.

Example: let's say that you quickly need to find the email of all registered users and send it to your buddy Jim in the marketing department.

$ mongo mongodb://my-fancy-mongo-server --ssl -u fancy_username -p fancy_password 
successfully connected to my-fancy-mongo-server!
> emails = db.users.distinct('email_address')
> writeFile("jims_email_list.json", tojson(emails))

or if Jim expect's a CSV file then

$ mongo mongodb://my-fancy-mongo-server --ssl -u fancy_username -p fancy_password 
successfully connected to my-fancy-mongo-server!
> emails = db.users.distinct('email_address')
> writeFile("jims_email_list.csv", emails.join("\n"))

You can now send Jim the list of emails and save the day!

To important things to notice about the writeFile function:

1. The second argument must be a string.
2. The first argument must be a file that doesn't already exist, otherwise you will get an error.