How to make a selection in MongoDB?

Question

MongoDB

I have a base with mobile phones. Let's say I want to make a selection on the operating system "iOS".
Intuitively tried to write something, but did not work out.

param: [{
            "@name": "Операционная система",
            "#text": "iOS"
        }]

How to implement it with such base? Screen is attached. It will be cool if immediately with the expectation of Mongoose.
I also don't understand what @ and # mean here.

Answer 1

Got it , https://docs.mongodb.com/manual/reference/operator...

{
        param: {
            $all: [
                { "$elemMatch": { "@name": "Операционная система", "#text": "iOS" } }
            ]
        }
}

https://msdn.microsoft.com/en-us/library/ms175874(...

Certain characters at the beginning of an identifier in SQL Server have a special meaning. A regular identifier that begins with @ signifies a local variable or parameter and cannot be used as the name of an object of any other type. An identifier that begins with a pound sign (#) indicates a temporary table or procedure. An identifier that starts with a double pound sign (##) means a global temporary object. Although the hash and double hash characters can be used at the beginning of other types of object names, we do not recommend this way of naming.