Reputation: 1285
My structure.
User:
{
name: "One",
favoriteWorkouts: [ids of workouts],
workouts: [ { name: "My workout 1" },...]
}
I want to get list of favorits/hottest workouts from database.
db.users.aggregate(
{ $unwind : "$favorite" },
{ $group : { _id : "$favorite" , number : { $sum : 1 } } },
{ $sort : { number : -1 } }
)
This returns
{
"hot": [
{
"_id": "521f6c27145c5d515f000006",
"number": 1
},
{
"_id": "521f6c2f145c5d515f000007",
"number": 1
},...
]}
But I want
{
hot: [
{object of hottest workout 1, object of hottest workout 2,...}
]}
How do you sort hottest data and fill the result with object, not just ids?
Upvotes: 0
Views: 354
Reputation: 891
You are correct to want to use MongoDB's aggregation framework. Aggregation will give you the output you are looking for if used correctly. If you are looking for just a list of the _id's of all users' favorite workouts, then I believe that you would need to add an additional $group operation to your pipeline:
db.users.aggregate(
{ $unwind : "$favoriteWorkouts" },
{ $group : { _id : "$favoriteWorkouts", number : { $sum : 1 } } },
{ $sort : { number : -1 } },
{ $group : { _id : "oneDocumentWithWorkoutArray", hot : { $push : "$_id" } } }
)
This will yield a document of the following form, with the workout ids listed by popularity:
{
"_id" : "oneDocumentWithWorkoutArray",
"hot" : [
"workout6",
"workout1",
"workout5",
"workout4",
"workout3",
"workout2"
]
}
Upvotes: 1