MongoDB SELECT COUNT GROUP BY

Question

I am playing around with MongoDB trying to figure out how to do a simple

SELECT province, COUNT(*) FROM contest GROUP BY province

But I can

Answer 1

Additionally if you need to restrict the grouping you can use:

db.events.aggregate( 
    {$match: {province: "ON"}},
    {$group: {_id: "$date", number: {$sum: 1}}}  
)