can we use populate with agreegate in mongo db?

questionsCategory: Questionscan we use populate with agreegate in mongo db?
Shyam asked 3 months ago

Hi,
i want to populate referance column in mongo DB, with Agreegate. How can i do it?
This is my appointment collection:

{ _id: ObjectId("518ee0bc9be1909012000002"), date: ISODate("2013-05-13T22:00:00Z"), patient:ObjectId("518ee0bc9be1909012000002") }

{ _id: ObjectId("518ee0bc9be1909012000002"), date: ISODate("2013-05-13T22:00:00Z"), patient:ObjectId("518ee0bc9be1909012000002") }

{ _id: ObjectId("518ee0bc9be1909012000002"), date: ISODate("2013-05-13T22:00:00Z"), patient:ObjectId("518ee0bc9be1909012000002") }

 

I used aggregate to get the following result

{date: ISODate("2013-05-13T22:00:00Z"),
patients:[ObjectId("518ee0bc9be1909012000002"),ObjectId("518ee0bc9be1909012000002"),ObjectId("518ee0bc9be1909012000002")] }

like this:

Appointments.aggregate([
{$group: {_id: '$date', patients: {$push: '$patient'}}},
{$project: {date: '$_id', patients: 1, _id: 0}}
], ...)
How can I populate the patient document I trued this but it doesn't work ... Appointments.find({}).populate("patient").aggregate....