CODEWITHSUNDEEP
mongodbmongooseaggregation-framework
Thales P
Thales P

Reputation: 371

Mongodb: How to return just the embedded document with aggregation framework

This is the doc structure where offers and bids is sub-documents. I use mongoosejs as ORM.

var user = {
    name : 'polk',
    offers: [{
        title: '1',
        tags: ['a', 'b', 'c'],
        bids: [{
            _id: 1      
            name: 'jose', 
            age: 18
        }, {
            _id: 2
            name: 'carlos', 
            age: 19
        }]
    },{
        title: '2',
        tags: ['d', 'e', 'f'],
        bids: [{
            _id: 3
            name: 'gomes', 
            age: 21
        }, {
            _id: 4
            name: 'fernando', 
            age: 31
        }]
    }]
};

What i need? This sub-document:

{
    _id: 4
    name: 'fernando', 
    age: 31
}

Using? Aggregation framework.

Upvotes: 0

Views: 880

Answers (1)

Parvin Gasimzade
Parvin Gasimzade

Reputation: 26032

You can do it as follows with Aggregation Framework : 

db.collection.aggregate(
    {$unwind : "$offers"},
    {$unwind : "$offers.bids"},
    {$match : {"offers.bids._id" : 4}},
    {$project : {_id : "$offers.bids._id", 
                 name : "$offers.bids.name", 
                 age : "$offers.name.age"
    }}
)

Upvotes: 2

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