No necesita $unwind
los workouts matriz ya que contiene una matriz de _id s y use $replaceRoot
en lugar de hacer $project
Users.aggregate([
{ "$match": { "_id" : ObjectId("whateverTheUserIdIs") }},
{ "$lookup": {
"from" : "workouts",
"localField" : "workouts",
"foreignField" : "_id",
"as" : "workoutDocumentsArray"
}},
{ "$unwind": "$workoutDocumentsArray" },
{ "$replaceRoot": { "newRoot": "$workoutDocumentsArray" }}
{ "$sort" : { "date" : -1 }}
])
o incluso con el nuevo $lookup
sintaxis
Users.aggregate([
{ "$match" : { "_id": ObjectId("whateverTheUserIdIs") }},
{ "$lookup" : {
"from" : "workouts",
"let": { "workouts": "$workouts" },
"pipeline": [
{ "$match": { "$expr": { "$in": ["$_id", "$$workouts"] }}},
{ "$sort" : { "date" : -1 }}
]
"as" : "workoutDocumentsArray"
}},
{ "$unwind": "$workoutDocumentsArray" },
{ "$replaceRoot": { "newRoot": "$workoutDocumentsArray" }}
])
