Starting:
mongo
Connect to database
show dbs
use local
See database tables
show collections
db.funnytable.find()
Regex
db.funnytable.find(
$or: [
{'name': { $regex: req.params.username, $options: 'i' }},
{'username': { $regex: req.params.username, $options: 'i' }},
{'email': { $regex: req.params.username, $options: 'i' }}
])