Awesome tutorial. It's always fun to mess around with things like this.
I am running into a problem with sorting though. On lesson 6 I am sorting with {weight:1} which the tutorial says is wrong, but I get the same answer as sorting on {weight: -1} which is correct according to the tutorial. Or is this a mongodb thing?
Anyway, keep up the good work.
MongoDB interactive tutorial
11–20 of 26 posts
Re: MongoDB interactive tutorial
#12In the real world you probably wouldn't want to have a dob field on the unicorns table. Instead just use the timestamp embedded into the _id field.
Pretty good overall though.
Re: MongoDB interactive tutorial
#13I'd love something like this for either Javascript itself or Node.js - Any ideas anyone?
Re: MongoDB interactive tutorial
#14Lesson 6 asks for 'Here's a tricky one: get ONLY the NAMES of the 2nd and 3rd heaviest male unicorns'
Which made me query:
db.unicorns.find({gender:'m'}, {name:1, _id:0}).sort({weight:-1}).skip(1).limit(2)
but it wants:
db.unicorns.find({gender:'m'}, {name:1}).sort({weight:-1}).skip(1).limit(2)
Re: MongoDB interactive tutorial
#15Lesson 6 asks for 'Here's a tricky one: get ONLY the NAMES of the 2nd and 3rd heaviest male unicorns' Which made me query: db.unicorns.find({gender:'m'}, {name:1, _id:0}).sort({weight:-1}).skip(1).limit(2) but it wants: db.unicorns.find({gender:'m'}, {name:1}).sort({weight:-1}).skip(1).limit(2)
Hey, thanks! I didn't know you could exclude the _id like that...I can actually make us of that trick. Going to push out a new version with that, and a few other fixes, in a few.
Re: MongoDB interactive tutorial
#16Awesome tutorial. It's always fun to mess around with things like this. I am running into a problem with sorting though. On lesson 6 I am sorting with {weight:1} which the tutorial says is wrong, but I get the same answer as sorting on {weight: -1} which is correct according to the tutorial. Or is this a mongodb thing? Anyway, keep up the good work.
weight:-1 is correct..since you want the heaviest, you sort by weight descending. weight:1 should have returned documents in ascending order but wasn't working. It's fixed now on the tutorial..as well as in the core web console:
https://github.com/karlseguin/Mongo-Web-Admin/commit/761cd4e...
Re: MongoDB interactive tutorial
#17Good tutorial.
After lesson 16 all the instructions disappeared and I was left with a white screen. Tried to go to a different lesson or the restart command but the instructions didn't come back. Couldn't replicate the problem unfortunately.
Re: MongoDB interactive tutorial
#18I still prefer the tutorial on the homepage of mongodb.org. Click "Try it out" and type "tutorial". This is very well done too, though.
Re: MongoDB interactive tutorial
#19Good tutorial. After lesson 16 all the instructions disappeared and I was left with a white screen. Tried to go to a different lesson or the restart command but the instructions didn't come back. Couldn't replicate the problem unfortunately.
ya, I've seen this but I can't reproduce it either. Really have no idea. Refresh and lesson(17); should at least let you continue from where you left off.
Re: MongoDB interactive tutorial
#20I tried the first one "It's easy, just enter db.getCollectionNames();" Received: "undefined method `collection_names' for nil:NilClass" Edit: It's relying on my cookie which wasn't enabled, oops. The official MongoDB interactive tutorial: http://try.mongodb.org/ Seems to be a clone of redis: http://try.redis-db.com/
Actually, the Redis one was a clone of MongoDB's.