CODEWITHSUNDEEP
mongodbmongooseaggregation-framework
Ростислав Падалко
Ростислав Падалко

Reputation: 227

How can i get array values from current field in document?

help me please : a have such order collection with this schema :

const OrderSchema =  new Schema(
{
    doctorId:       { type : Schema.Types.ObjectId, ref: 'Users'},
    patientId:      { type : Schema.Types.ObjectId, ref: 'Users'},
    orderTime:      { type : String , default:''},
    createdAt:      { type : Date, default:Date.now },
    approvedByDoctor:{ type :Boolean, default:false },
    price:{type:Number,default:0}
},

);

and a have 10 documents like this, what query must i do to get array of "orderTime" from each document? thanks

Upvotes: 1

Views: 36

Answers (2)

robjwilkins
robjwilkins

Reputation: 5652

Assuming you have documents which look like this:

{
        "_id" : ObjectId("578f73d17612ac41eb736641"),
        "createdAt" : ISODate("2016-07-20T12:51:29.558Z")
}
{
        "_id" : ObjectId("578f73e57612ac41eb736642"),
        "createdAt" : ISODate("2016-07-20T12:51:49.701Z")
}

then you can generate a result document containing an array of createdAt dates which looks like this:

{ "_id" : null, "creationDates" : [ ISODate("2016-07-20T12:51:29.558Z"), ISODate("2016-07-20T12:51:49.701Z") ] }

by running the following aggregate query:

db.<your_collection>.aggregate([{$group:{"_id":null,"creationDates":{$push:"$createdAt"}}}])

this will basically group all documents in the collection ("_id":null) and push the the values from the createdAt fields into an array ("creationDates":{$push:"$createdAt"})

Upvotes: 2

chridam
chridam

Reputation: 103305

Use the aggregation framework to create the array. Essentially you'd want to group all the documents, use the $push accumulator operator to create the list. Follow this example to get the gist:

Order.aggregate([
    {
        "$group": {
            "_id": 0,
            "orderTimes": { "$push": "$orderTime" }         
        }
    }
]).exec(function(err, result) {
    console.log(result[0].orderTimes);
});

Upvotes: 1

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