Result of findOne method without value type

Working with Data
1

This is part of my document:

"gameData": {
   "gold": 0
}

Through the findOne method, I wanted to obtain the value of “gold” in the document.

myCollection.findOne( 
   { "userData.username": username},
   { "gameData.gold":  1, "_id": 0} 
);

The result is: {"gameData":{"gold":{"$numberLong":"0"}}}

I wanted to know if it was possible to have only the value of “gold” as a result, or a normal JSON without the “$numberLong” key (I’m not sure but I think the current result is in BSON format, but I couldn’t find a function to convert it to JSON).

Thanks.

2

Hello Andrea,

The value of gold is in JSON format, in the output. It is the the MongoDB representation of BSON value in JSON format. See:

To get the value of gold field’s value only from the embedded document gameData, you can use one of the following ways from mongo shell:

const doc = db.test.findOne( { }, { "gameData.gold":  1, "_id": 0 }  );
printjson(doc.gameData)

Prints: { "gold" : NumberLong(12345678) }

Or, an aggregation query:

db.test.aggregate( [ 
    { 
        $project: { _id: 0, gold: "$gameData.gold" } 
    } 
] )
3

Hi @Prasad_Saya ,
thank you for your answer.
So there is no possibility to receive a string like { "gold" : 12345 } as return?

4

You can. The default numeric data type for MongoDB is a double. If you dont use any type it will be a double. So, convert the long to a double and you get the result in the desired format.

db.test.aggregate( [ 
    { 
        $project: { _id: 0, gold: { $convert: { input: "$gameData.gold", to: "double"  } } }
    } 
] )
5

Hii @Andrea

I assume that since we chatted about MongoDB realm this is a return of a document from a webhook in EJSON format which is what could be expected when just returning it.

However, you could set the response body with the query result parsed to JSON:

doc = await myCollection.findOne( 
   { "userData.username": username},
   { "gameData.gold":  1, "_id": 0} 
);

response.setBody(JSON.stringify(doc));

See this docs:

Let me know if I am correct. :slight_smile:

Best regards,
Pavel

1 Like
6

Thank you both very much for your answers!
Pavel, you understood perfectly what I needed. Thank you very much!

7

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