Export Mongo query result to CSV

export.js

db.getCollection('event').find({whatever_field: 'value'}).forEach(function(u) {
   print('"' + u._id + '";"' + u.createdAt.toJSON() + '";');
});

shell_exec.sh

 mongo db_name --username db_user --password db_password export.js > export.csv
 

Simply create the javascript file and put it somewhere on your server. Next, execute the mongo command. Javascript will loop over the results and output every line to a csv file. That's it.