How to get the element value in the mongodb array

Question

I have many songs contained in a collection, each containing _id and description, in the description is an array of elements including line and sub_fingerprint, I pass on _id and line. How to retrieve subfingerprint? Thanks I have a mongo command called

db.getCollection ('song_fingerprint'). Find ({_id: 1},
                  {Fingerprint: {$ elemMatch: {line: 102}}})

But in Java it is very difficult ...

{
    "_id" : 13,
    "fingerprint" : [ 
        {
            "line" : 1,
            "sub_finger" : "74076e76"
        }, 
        {
            "line" : 2,
            "sub_finger" : "74076ef6"
        }, 
        {
            "line" : 3,
            "sub_finger" : "74076ef6"
        }, 
        {
            "line" : 4,
            "sub_finger" : "74056ef6"
        }, 
        {
            "line" : 5,
            "sub_finger" : "76856ed6"
        }, 
        {
            "line" : 6,
            "sub_finger" : "76e52ed6"
        }, 
        {
            "line" : 7,
            "sub_finger" : "76e58cd6"
        }]
}

I think this is what you want http://stackoverflow.com/q/3985214/7420795 — user7420795, Apr 21 '17 at 05:18

score 0 · Answer 1 · answered Apr 21 '17 at 06:02

0

i have tested in my local its working it's returning corresponding element in json

db.getCollection('song_fingerprint').find({"fingerprint.line" : 2},{_id: 13, fingerprint: {$elemMatch: {line: "2"}}})

answered Apr 21 '17 at 06:02

Narendra

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How to get the element value in the mongodb array

1 Answers1