MongoDB error on find() - mongodb

Question

I'm just started to create my MongoDB schema (im newbie on mongo), my schema looks like this example:
users : [
{
_id : 11,
name : "jhon",
mail : "jhon#mail.com"
},
{
_id : 12,
name : "smith",
mail: "smith#mail.com"
}
]
I want to retrieve certain user information, bsaed on a _id...
For example:
db.users.find({"users._id" : 11})
And then my result should be:
_id : 11,
name : "jhon",
mail : "jhon#mail.com"
but the result i get is all the users of the users document, i just one one, the one who have certaint _id.
How can i write a query for that?.
And just in case, my schema is designed properly?
Thanks for the help! :)

Answer 1

Try with this
db.users.find({"_id" : 11})

Answer 2

You ask whether your schema is designed properly. That of course depends on your use case, but the answer is probably... no. Instead of a single document with an array, probably what you want is multiple documents. For example, I inserted some documents using the mongo shell:
> db.users.insert({_id: 11, name: "jhon", mail: "jhon#mail.com"})
> db.users.insert({_id: 12, name: "smith", mail: "smith#mail.com"})
Then here's a query typed at the mongo shell that will return all documents:
> db.users.find()
{ "_id" : 11, "name" : "jhon", "mail" : "jhon#mail.com" }
{ "_id" : 12, "name" : "smith", "mail" : "smith#mail.com" }
And if you have the _id, you can query just that document:
> db.users.findOne({_id: 11})
{ "_id" : 11, "name" : "jhon", "mail" : "jhon#mail.com" }
Arrays have their uses, but the kind of thing you are doing here is usually done with multiple documents in a collection, rather than sub-documents within an array.
Does this help?