mongoose vs mongodb (nodejs modules/extensions), which better? and why?

Mongoose is higher level and uses the MongoDB driver (it's a dependency, check the package.json), so you'll be using that either way given those options. The question you should be asking yourself is, "Do I want to use the raw driver, or do I need an object-document modeling tool?" If you're looking for an object modeling (ODM, a counterpart to ORMs from the SQL world) tool to skip some lower level work, you want Mongoose.

If you want a driver, because you intend to break a lot of rules that an ODM might enforce, go with MongoDB. If you want a fast driver, and can live with some missing features, give Mongolian DeadBeef a try: https://github.com/marcello3d/node-mongolian

Mongoose is, by far, the most popular. I use it, and have not used others. So I can't speak about the others, but I can tell you my gripes with Mongoose.

• Difficult / poor documentation
• Models are used. And they define structure for your documents. Yet this seems odd for Mongo where one of its advantages is that you can throw in a column (err, attribute?) or simply not add one.
• Models are case sensitive - Myself and other devs I work with have had issues where the case of the collection name that the model is defined with can cause it to not save anything, w/o error. We have found that using all lowercase names works best. E.g. instead of doing something like mongooseInstace.model('MyCollection', { "_id": Number, "xyz": String }) it's better to do (even though the collection name is really MyCollection): mongooseInstace.model('mycollection', { "_id": Number, "xyz": String })

But honestly, it's really useful. The biggest issue is the documentation. It's there, but it's dry and hard to find what you need. It could use better explanations and more examples. But once you get past these things it works really really well.

I'm building new app and designing now structure of it, here are some thoughts about why to use or not to use mongoose:

1. Mongoose will be slower (for big apps)
2. Mongoose is harder with more complicated queries
3. There will be situations when you want more speed and you will choose to go without mongoose then you will have half queries with mongoose and half w/o. That's crazy situation, had once..
4. Mongoose will make you code faster with simple apps with simple db structure
5. Mongoose will make you read mongodb docs AND mongoose docs
6. With mongoose your stack will get one more thing to depend on and it's one more possibility to crash and burn to ashes.

mongodb driver is raw driver, you communicate directly to mongodb.mongoose is abstraction layer. You get easier I/O to db while your db structure is simple enough.

Abstraction brings in it's requirements and you have to follow those. Your app will be slower, eat more RAM and be more complicated, but if you know how to use it, you can faster write simple objects, save those to database.

Without mongoose you will have faster application with direct connection to mongodb. No-one says, that you can't write your own models to save stuff to db. You can. And I think it's easier. You write code, which you will use, you know what you need. You abstraction layer will be way smaller, then mongoose's.

I'm coming from PHP world, there we had raw sql with depreciated mysql_ functions, then we got PDO - object orientated abstraction layer to communicate with sql. Or you can choose some heavy ORM like Doctrine to have similar stuff to mongoose on mongoDB. Objects with setter/getters/save method and so on. That's fine, but by adding more abstraction you are adding more files, more logic, more documentation, more dependencies. I like to keep stuff simple and have less dependencies in my stack. BTW, that was why I moved from PHP to server-client Javascript in first place..

With mongoose I think is great to write some simple apps, that have simple db structure similar to sql. When you start having subdocuments and want to make all those crazy queries i found it really hard with mongoose. You have to look at mongodb docs, then look at mongoose docs to find out how to make a query you want. Sometimes you will find, that X future of mongodb is not in mongoose, so you go down to raw mongodb driver and write raw mongodb queries in one or another place. Without mongoose, you look at mongodb docs and do your query.